CPRR/SP Donner Route Timeline

Each monthly issue of the PSRHS newsletter has featured a brief paragraph on a segment of the history or operation of the Donner Route. Initially the paragraphs tracked the construction of the original transcontinental railroad over Donner Pass to the connection with UP in Utah. Subsequent issues highlighted modifications made to the tracks or operations along the route from Roseville to Truckee. What follows is a compilation of those paragraphs, appearing in newsletter issues from April 2011 to November 2016, and providing an abbreviated history of the route.

CPRR/SP Donner Route Timeline — As Reported in Monthly PSRHS Newsletters (one paragraph each month)

January 8, 1863: Ground breaking ceremonies take place at Sacramento, California, at the foot of “K” Street at the waterfront of the Sacramento River

CPRR engine #1, Governor Stanford, a 4-4-0, arrived by ship at Sacramento in October 1863. On Feb. 18, 1864, the Governor Stanford pulled an excursion train to end-of-track two miles west of Junction (renamed Roseville – mile 18). Guests rode on benches on open platform cars – passenger cars were being built but not yet ready for service. At Junction the Central Pacific connected with the California Central Railroad, building from Folsom toward Lincoln.

On March 19, 1864, the Governor Stanford pulled an excursion train with two recently completed passenger cars. The destination was the granite quarries at Rocklin, the new end-of-track. The first revenue train operated on the Central Pacific March 25, 1864, carrying granite from the Rocklin quarries to Sacramento.

The CP unveiled its second operating locomotive, the Pacific, in March 1864. Also in March, two tank engines, the CP Huntington and TD Judah, arrived unassembled by ship at San Francisco, and were added to the active roster in April 1864. Also arriving by sea were a supply of rails, fifteen boxcars, thirty-five platform cars, and two passenger cars, all knocked down but ready for assembly.

April 16, 1864 – Placer Herald report on Bloomer Cut Accident: “Yesterday on the deep cut of the of the Pacific Railroad, near town, some of the workmen under the superintendence of Mr. Trowbridge [sic] attempted to set off a blast containing about 50 pounds of powder. From some cause it failed, when Mr. T. [sic], and two of the hands, – a Portuguese and a Frenchman – commenced using a crowbar or drill upon the hole, when the blast went off suddenly, mutilating them in a horrible manner, especially the Portuguese who is not expected to recover; but Mr. Trobridge [sic] will, with probably the loss of his left eye.”

April 25, 1864: Central Pacific began regular passenger service to Roseville, 18 miles (29 km) from Sacramento, operating three trains daily in each direction, with connections at Roseville to the California Central Railroad. First week revenue for 298 passengers equaled $354. In comparison, the engine Pacific cost $15,000 to purchase and ship from the east coast.

Summer 1864 – Charley Crocker had the contract to build the rails to Junction (Roseville), but public criticism of the arrangement led to awarding the construction from Roseville to Newcastle to competing firms. This resulted in many problems – one firm went bankrupt, work further up the line was completed before lower work, and firms competed for laborers. Charley Crocker’s firm was back in control for the construction work above Newcastle.

June 1864: Tracks reached Newcastle in May, 1864, and the first revenue train between Sacramento and Newcastle operated on June 3, 1864. Central Pacific RR Time Card No. 1 took effect June 6, 1864 at 5AM. Three trains each way were listed, with two of them operating daily except Sunday, and one operating daily. Work was underway on the next major obstacles, the Newcastle trestle and Bloomer Cut.

June 1864: Shortly after the rails reached Newcastle, the associates opened their wagon toll pike, the Dutch Flat and Donner Lake Road. Teamsters could travel between the Newcastle railhead and the mining camps near Virginia City, saving three days over the route through Folsom and Placerville. Passengers could travel by train from Sacramento to Newcastle, then by coaches of the California Stage Company to Virginia City, in about 17 hours.

There were some 1200 laborers, many of them Irish, on the company payroll in early 1865, working on Bloomer Cut and the grade above Newcastle, under the direction of Charley Crocker and his construction boss, James Strobridge. Two survey crews preceded the construction crews, one just ahead of construction, and the other pressing toward the Sierra summit.

On May 13, 1865, Central Pacific opened 36 miles to Auburn. Tracks reached Clipper Gap June 10. During the construction from Newcastle to Clipper Gap Chinese workers were first hired by Crocker and Strobridge, and were initially assigned to the menial task of loading dump carts. The Chinese soon proved to be more reliable than the Irish crews, who tended to disappear after payday or leave to try their luck at mining.

In July 1865, the new town of Colfax was laid out on land purchased by CPRR, and tracks were soon being laid on the newly completed grade to the townsite. In September 1865, Central Pacific opened 54 miles of track from Sacramento to Colfax, with the first trains operating to and from the town on Sept. 4. The long CPRR freight shed in Colfax quickly replaced nearby Illinoistown as the loading point for wagons carrying supplies to nearby mines and communities.

In August 1865, grading began above Colfax, and work also began on Summit Tunnel 6. Judah’s original survey had located the grade on the Bear River side of the ridge at Illinoistown to Long Ravine, but later surveys showed the present route to be better. The grade above Colfax involved building a curved trestle and bridge at Long Ravine, and carving a roadbed out of rock around Cape Horn. The assault on the high Sierra had begun in earnest.

Two miles from Colfax, the route rapidly gained elevation. At Cape Horn, the roadbed was carved out of a cliff. Reports indicating that Chinese workers were dangled over the cliffs in baskets have largely been disproven by analysis of the slopes. This conclusion does not diminish the accomplishment, however. Cape Horn was an engineering feat that cemented Strobridge’s faith in the Chinese workers. No lives were lost in constructing this section of the CPRR.

CPRR started 1866 with 54 miles of track, reaching from Sacramento to Colfax. By early spring 1866, there were over 10,000 men at work on the route. That spring major construction projects were completed at Long Ravine bridge and trestle, Cape Horn, SecretTown trestle, and the excavation at Dixie Cut. Tracks reached SecretTown in May 1866, Dutch Flat in June, and Alta on July 15, 1866

CPRR tracks reached Cisco, 94 miles from Sacramento, in November 1866. Through cars were operating to Cisco by early December. On December 19, 1866, the vertical shaft at Summit tunnel was completed. Tunnel boring could now proceed at four locations. Workers built snow tunnels so that construction could continue on the Summit tunnel through the harsh winter of 1866-67.

During the harsh winter of 1866/1867, Cisco was abandoned and tracks were kept open to Alta. Grading and track work was impossible on the summit, so crews were sent to Truckee. Teamsters hauled a locomotive, 40 cars, and material to build 40 miles of track to Coburn’s Station (Truckee). Track-laying forces did not return to the summit until June 1867.

Summit Tunnel 6 was holed through on Aug. 30, 1867. Tracks from Cisco reached the summit tunnel on Nov. 30, 1867. On Dec. 1, 1867, Central Pacific opened 105 miles of track from Sacramento to the summit of the Sierra Nevada. Tracks reached two miles beyond Summit station when winter set in.

While work at the summit was suspended during the 1867-68 winter, construction continued east of Coburn’s Station (now Truckee). On Dec. 13, 1867, the first Central Pacific locomotive nosed into the state of Nevada. On May 4, 1868, tracks reached 14 miles east of the California/Nevada state line. An auction for town lots was held on May 9, and Reno sprouted into existence.

On June 18, 1868, the seven mile gap from Summit to Coburn’s Station (Truckee) was completed, and the first through train entered Coburn’s on June 19. By July 22 tracks reached Wadsworth, NV (mile 188), where a division yard and repair shops were erected. It had taken five and a half years to build the 188 miles from Sacramento to Wadsworth. The next 501 miles to the junction with the Union Pacific were built in nine months

On April 28, 1869 track crews on the Central Pacific laid 10 miles of track in one day. This is the longest stretch of track that has been built in one day to date. The Central Pacific and Union Pacific tracks met in Promontory, Utah on May 10, 1869. The first transcontinental trains ran over the new line to Sacramento on May 15.   The nation’s first Transcontinental Railroad was now an operating reality.

With construction complete between Sacramento and the East, the CP turned its attention to completing a rail link from Sacramento to San Francisco. The CP acquired the Western Pacific Railroad (not the later WP), and in September 1869 completed the new line from Sacramento to Alameda via Stockton, Livermore and Niles. A month later the track was extended to Oakland. Ferries transported passengers to San Francisco until a rail link was established via San Joss and the San Francisco and San Jose Railroad.

In November 1869, UP sold 48.5 miles of its track east of Promontory Summit to the CP and leased another 5.5 miles. This allowed the CP to operate its trains from Sacramento to Ogden. The official junction between the two railroads was formally changed to Ogden from Promontory in December 1869. The CP rebuilt some 10 miles of the original UP grade east of Promontory Summit (on grade CP had surveyed) in 1870, replacing some of the UP’s steep grades and tight curves.

Snowsheds – Before rail construction over Donner was completed, heavy snows made it clear that some protection was needed to keep the new line open in winter. Snowshed construction was started soon after rails were laid, and by the early 1870’s more than 30 miles of sheds were complete. The snowsheds started at Blue Canyon, and were nearly continuous from Emigrant Gap to Andover. Early sheds were an A-frame design, but experience soon showed that a flat slanted-roof design was preferable, anchored into the hillsides.

On June 23, 1870, Central Pacific was consolidated with the Western Pacific Railroad (1862-1870) and San Francisco Bay Railroad Co. to form the “Central Pacific Railroad Co.” (of June, 1870). On August 22, 1870, Central Pacific Railroad Co. was consolidated with the California & Oregon; San Francisco, Oakland & Alameda; and San Joaquin Valley Railroad; to form the “Central Pacific Railroad Co.”, a new corporation.

Improvements were needed almost immediately on some portions of the transcontinental route. By 1873 iron rail over Donner was being replaced with 60-pound steel rail. Trestles below Colfax and at Clipper Gap were filled in. At Deep Gulch east of Clipper Gap, one of the highest trestles on the line was abandoned when a new tunnel (Tunnel 0) was completed and the trestle bypassed. Repairs to other trestles between Newcastle and Secret Town assured their safe use for at least 3-5 more years.

CPRR acquired California Pacific Railroad in 1876, giving it a route from Sacramento to Vallejo with steamboat link to San Francisco. In 1879, CPRR completed a line via Suisun Marsh to Benicia, where train cars and passengers were transported across the Carquinez Strait on large ferries to Port Costa, then back on land route to Oakland. These ferries operated until the 5600-foot double-track Benicia-Martinez bridge was completed in 1930.

In his Chief Engineer’s report in 1877, Montague reported “The most important permanent improvements made upon your road during the year 1876 have been the filling of all the high trestles remaining on the Sacramento division” including trestles at Newcastle, Auburn, Lovell’s Mill, Clipper Gap, Long Ravine, and Secret Town. He further stated “This completes the work of this kind on the mountain division” except for possible replacement of the Howe Truss bridge at Long Ravine with an embankment, but the bridge should not need renewal for 12-15 years.

When the Long Ravine trestle was filled in 1876, CPRR briefly considered filling in the bridge portion as well, and NCNG Railroad began making plans to build an arch where their line crossed under what was to become fill to replace Long Ravine Bridge. However, the wooden Howe Truss bridge remained in place until 1890 when the Dept. of Interior’s Report of the Commissioner of Railroads stated “Long Ravine: An Iron bridge was built to replace the wooden structure”, the first of two steel railroad bridges that today span Long Ravine on the Donner Pass Route.

Changes and improvements required due to repair and maintenance were made permanent in the late 1870’s, with an eye toward economy in future repairs. Steel rail continued to be installed on new sidings and in track repairs, and 940,000 ties were used in 1878 and 1879.Over 4800 feet of snowsheds were lost to fire and replaced in 1878, along with 1200 feet of shed near Owl Gap in 1879. New woodsheds were constructed in 1879 at Rocklin, Clipper Gap, Colfax and Alta.

The Chief Engineer’s Report in 1882 reported that the new pier and passenger terminal were completed at the Port of Oakland in 1881. The pier was more than a mile long and 280 feet wide. Four tracks extended 4800 feet to its end. The depot building was 1050 feet long and 120 feet wide, with 60-foot wide side buildings. Ten tracks extended through the building. Two large passenger waiting areas were provided, along with offices for the Division Superintendent.

The Chief Engineer’s Report in 1882 reported that the Truckee yard had been rearranged and a new 22-stall roundhouse built with local granite. The 1886 report stated that bridges had been renewed at Truckee and Prosser Creek, and over 6500 feet of snowsheds overhauled and repaired at Blue Canyon, Tunnel 2 and Butte Canyon Bridge.

Branch lines began to appear along the Donner Route to provide rail connection to locations not directly served by CPRR. In 1876 the Nevada County Narrow Gauge Railroad began operating from its mainline connection in Colfax to the gold mining districts near Grass Valley and Nevada City. Provided passenger and freight service, the line replaced a slow wagon road and stage line that were often made impassible by weather. Rail service on the NCNG continued until 1942.

After tracks were completed to Alta in 1866, a siding one mile above Alta at Alta Shed served Towle Brothers’ growing logging empire. In the mid-1870’s, Towle Brothers built a narrow gauge logging railroad that extended over 30 miles from the Alta Shed siding into Nevada County. In 1883 Central Pacific established a station stop there called Towle’s. The company town boasted a hotel, store, planer, box factory, and pulp mill until 1902 when the company was sold.

One of the first major changes to the Donner Route came in the early 1900’s. As traffic increased, SP expanded its yard area at Rocklin in 1903, but the expansion was inadequate and a new location was sought for the major yard and site for adding helper engines for the steep grade over Donner. Roseville was an ideal location since it also served as the junction for the northern lines.   Work began on the new Roseville yard in 1906, and by 1907 operations were shifting from Rocklin to Roseville. Rocklin crews held a “funeral” for the Rocklin roundhouse in 1908.

Staff System — As traffic increased on the Donner route, control of trains on the single track became a growing issue. To avoid the expensive track circuitry needed to convert to automatic block signals, a manual “staff” system was implemented in 1905 from Rocklin to Truckee. Manned staff stations were located about every 3 miles. At these stations the engineer picked up a wooden or metal staff that gave that train the right-of-track between that and the next staff station. The staff system was gradually phased out as double tracking was completed over the next two decades.

Area newspapers were abuzz in 1901-02 with the reports that Southern Pacific, then under E.H. Harriman’s control, was surveying two possible tunnels under Donner Summit. Benefits would be reduced running time due to reduced grades and mileage, and elimination of some of the costly snowsheds. One tunnel would run from the American River Canyon some 6 miles to the Stanford Curve. The other would run some 5 miles from Soda Springs station to the north shore of Donner Lake. Huge construction costs and need for electrification eventually doomed these ventures.

Double-Tracking — In 1911 SP began grade modifications and double-tracking between Rocklin and Colfax. Two contracts were awarded for the work, one contractor working between Rocklin and Clipper Gap, the other between Clipper Gap and Colfax. To reduce grades, the new roadbed at times deviated from the original tracks, and at other times paralleled or crossed the original mainline, creating major challenges for contractors to ensure daily rail traffic was not interrupted during construction. The new grade resulted in left-hand running on portions of the new mainline, with eastbound traffic using the new #2 track.

To ease the uphill grade between Rocklin and Newcastle as part of double-tracking, the new eastbound track crossed over the old track just north of Rocklin becoming left-hand running, then skirted the hillside behind Loomis through three new tunnels. Old and new tracks rejoined at Newcastle, then followed a new alignment into double-tracked Tunnel 18. The eastbound track bypassed the Loomis station, so local trains ran both directions on the westbound track between Loomis and Rocklin.

In 1911 the hillside at the south edge of Colfax was cut away to make way for the new double tracks, a large yard and engine house southwest of Grass Valley Street. At several locations along the double tracking project the new track and old track ran close to each other. Some sections of the winding original roadbed that hugged the hillsides were abandoned and the old tracks moved to the new straightened alignment. Many of these abandoned roadbed segments can be found today along the route.

East of double-tracked Tunnel 18 at Newcastle, the new eastbound track angled north of the old track and traversed Auburn Ravine on a trestle that today crosses over Interstate 80. While the trestle was being erected, construction equipment was transported on temporary tracks laid along Sacramento Street through Old Auburn to Nevada Street and up the opposite side of Auburn Ravine, where railroad construction work continued while the trestle was being completed. A new Nevada Street Depot was built near the present-day Echo Valley Ranch Feed Store. At Bowman the new eastbound track rejoined the old track but at slightly different elevations.

Beyond Bowman the old and new tracks ran nearly parallel until reaching Clipper Gap. Just beyond Clipper Gap the hillside was cut away and both tracks were moved to a new alignment. Near Tunnel 0 new tunnels 23, 24 and 25 carried the eastbound track along an elevation lower than the old track. The new track crossed under the old at Tunnel 26 near Applegate, shifting the traffic flow back to right-hand running. The new eastbound track continued at a lower elevation through Tunnels 27-32 before rejoining the old track near Illinoistown gap. From there westbound and eastbound tracks were laid side-by-side on new grade into the new yard at Colfax.

With the new double track and yard in Colfax completed by 1913, mainline tracks west of Grass Valley St. now ran at a slight angle to the passenger depot. At Grass Valley St. the tracks curved to the left onto the old alignment past the freight depot. The 1905 turntable near Oak St. was soon abandoned, replaced by the new wye track near the 9 stall Colfax engine house. Colfax-based helper engines were added to the front of eastbound trains for the steep grade ahead. Many trains also had a helper cut in near the end of the train at Roseville. The Roseville helpers were cut and turned at Summit, while Colfax helpers were cut and turned at Emigrant Gap.

In 1910 local newspapers contained the first talk of double-tracking work commencing above Colfax. However, the work stalled and in December 1910 a newspaper reported that SP might be planning to standard-gauge the route from Colfax to Grass Valley, then through Beckworth Pass to Reno, bypassing the route above Cape Horn. Rumors of surveyors in the Grass Valley area kept this story alive until late 1912 when work began in earnest above Colfax. In 1913 removal began on the hill in Colfax east of the tracks and beyond Grass Valley St. By 1914 double track was complete from Colfax to Wirt near Long Ravine, with only yard alignment to be rectified in Colfax.

With double-tracking underway above Colfax, focus within the town was on track realignment. Removal of the hillside northeast of Grass Valley St. created a straight path through town for the new tracks. But before the tracks could be moved the Nevada County quartz monument and the freight depot had to be relocated out of the new right-of-way. The quartz monument was moved to the north side of Grass Valley St. between the new alignment of NCNG and mainline tracks. The freight depot was moved to the Main St. side of the tracks in 1915, where it still sits today. A new transfer shed was built in the yard area near the engine house to transfer cargo between NCNG and SP cars.

In 1913-1914 double tracking from Colfax to Blue Canyon was underway in earnest. For the most part the second track was laid parallel to the original track. This involved widening Tunnel 1 to make room for the second track, and building a second steel viaduct crossing Long Ravine, which was completed in 1914. Also completed in 1914 were double-track tunnels 33 and 34 at Cape Horn that bypassed the scenic trip around the Cape. But double tracking in the tunnels was short-lived. With tight clearances for meets between large locomotives and gas build-up for eastbound trains, the second track within the tunnels was soon abandoned and eastbound trains returned to the old tracks around Cape Horn.

The new second track between Colfax and Blue Canyon was inspected and put into service in early 1915. Several of the staff stations along this route were abandoned as they were no longer needed to control train traffic on a single track, but some stations remained as telegraph stations. Meanwhile double track work between Reno and Truckee was also completed in 1915. However, double-tracking between Truckee and Blue Canyon would not get underway for nearly a decade, with the future of the line held up by ongoing government lawsuits over whether the Central Pacific should be controlled by SP or UP, or be a separate entity. That issue was finally decided in SP’s favor in June 1923.

In 1923, with control of Central Pacific safely under its wing once again, SP secured funding to continue double tracking of the Donner Route. By August a second track was laid from Blue Canyon to Emigrant Gap. Included at Emigrant Gap were a center siding and 80 foot turntable. Also in August a second track was completed from Truckee to Andover. But building a second track from Andover to Emigrant Gap presented major challenges. The new track was adjacent to the operating track much of the way and often in snowsheds. Some sheds had to be temporarily removed to allow access for construction equipment. The 10,322-foot Tunnel 41 at the summit was holed through in August 1925, and the second track was in use by September of that year.

The completion of the second track over Donner Summit saw several miles of snowsheds removed and not replaced, but the new line included 7 new tunnels. While the new track closely paralleled the original track for most of the route, the new track running to the west portal of Tunnel 41 diverged from the old track at what became Norden. Both this stretch of new track and the entire Norden complex were under new snowsheds. The Norden complex included passing sidings for both the old and new tracks and a covered 120 foot turntable capable of turning the large cab-forward helpers. In early 1926 Norden assumed the helper, maintenance and communications operations formerly carried out at Summit, which was soon abandoned.

While not directly on the Donner Route, one other major change occurred along the line at the end of the 1920’s. Since 1879 trains traveling from Sacramento to Oakland were transported across the Carquinez Strait on large ferries from Benicia to Port Costa. The ferry Solano was impressive – over 400 feet long and 100 feet wide. Its four on-board tracks could accommodate 24 of the largest class passenger cars. In 1930 the new 5600 foot double-track Benicia-Martinez bridge was completed and the ferries were no longer needed. If you know where to look the rotting remains of one of the ferries may still be found along the waterfront upstream from the bridge near the town of Pittsburg.

With completion of Summit Tunnel 41 in 1925 and the Benicia-Martinez railroad bridge in 1930, Southern Pacific now boasted nearly 250 miles of continuous double track from the Oakland Pier to Sparks, Nevada. Along with double-track operations and improved snow fighting equipment came a gradual reduction in costly snowsheds, until by 1950 only a few miles remained. In the Truckee area SP leased the Lake Tahoe line in 1925 and standard-gauged it in 1926. The line operated between Truckee and Tahoe City until abandoned in 1943.

While no other major construction or track changes would take place on the Donner route until late in the 20th century, big changes were still in the air. Steam had ruled over Donner since the first steam locomotive crossed the summit in 1868. Locomotives kept getting larger, capped by the fleet of cab-forwards unique to SP that began appearing in 1910. By the 1930s these cab-forwards were the workhorses of the mountain. But in 1936 the streamlined “City of San Francisco” made its debut on the route, powered by new diesel locomotives. Soon freight diesels began to appear, first as helpers, then as main power with cab-forward helpers.

The 1940’s war years saw extra trains added to move troops and equipment to coastal ports, and to return troops home at the end of the war. Steam locomotives were still in their prime, but more passenger and some freight diesels were appearing by the late 1940’s. Use of Colfax steam helpers was discontinued and in 1949 the Colfax engine house was closed for good. As more diesels were delivered steam locomotives including cab forwards were soon relegated to helper service. The decision was made in 1955 to cut back on steam locomotive use on Donner, but they persisted into 1956. The last run of a cab-forward (#4274) occurred on a special excursion in late 1957, and the last official steam-powered run over Donner was GS #4460 on another excursion in October 1958.

While the construction of Interstate 80 in the 1950’s and ‘60’s did not directly change the railroad right-of-way, there were several impacts on railroad structures or crossings. A bridge was added at Newcastle to carry the tracks over the new freeway. At Auburn Ravine, a girder bridge was placed under the tracks to increase the span for the wider freeway. And at Long Ravine a girder bridge replaced one of the steel support piers to make room for the freeway to pass under the Long Ravine bridges. At Emigrant Gap old Hwy 40 went under the tracks but the new freeway crossed over the tracks. Additional bridges carried the freeway over the tracks at Bowman, Towle and Yuba Gap. Some remaining buildings at Towle were displaced by the freeway construction.

One more major change to the Donner Route was yet to be implemented while still under SP control – the elimination of sections of double track near Donner Summit. The Feb. 1994 issue of Trains Magazine announced that SP planned to single-track 105 miles of the Donner Pass line from Colfax to Sparks. SP cited economics, drop in tonnage, and costs to maintain the difficult line and keep both tracks open in winter. The company had been losing business to UP after the latter took over WP’s parallel route, and SP managers planned to shift the rail to other SP lines where business was stronger. They were also considering single-tracking from Colfax to Roseville and Sacramento to Martinez. In its Sept. 1994 issue Trains reported that SP had removed the second track on two segments, 7.1 miles east from Emigrant Gap, and the original CP track from Norden through Tunnel 6 to Shed 47. If SP still planned to remove the rest of the second track to Colfax, those plans were likely set aside when UP began negotiations to take over SP operations.

UP Takes Over — The 1996 merger of Southern Pacific into the Union Pacific system settled a long-standing struggle for control of the two competing lines that dated back to the original construction of the transcontinental railroad in the 1860’s. UP now controlled the line that includes the Donner crossing from San Francisco Bay to Omaha and beyond. SP colors were soon replaced by UP yellow, and today only an occasional glimpse is seen of former SP markings on passing locomotives or freight cars. Under UP ownership one major construction change has been implemented over Donner. Tunnel heights were raised or floors lowered to allow double-stack container trains to travel the Donner route rather than Feather River Canyon. Not all tunnels were modified, though, and between Bowman and Colfax eastbound double-stack trains must cross over to the old number one track, transferring back to the number two track just west of Colfax at a new high-speed crossover. A westbound freight waiting just east of Colfax probably means an eastbound double-stack is making its way uphill on the number one track.

In recent years wood ties on portions of the Donner route mainline tracks have been replaced with concrete ties. Wooden ties have been used since early railroad days, but had to be replaced regularly due to damage from the punishing effects of heavy rail traffic. Concrete ties are more durable but are also more expensive to purchase. Where concrete ties have been installed, rail spikes in wood ties have been replaced with bolt-down fasteners. But not all wood ties are being replaced with concrete. In 2016 new wood ties were installed on a large section of mainline track above Colfax.