all east and west bound traffic between Norden and Shed 47 over a single track. (To eliminate bottleneck delays the now single track section between Switch 9 (MP 171.9) at Emigrant Gap and Shed 10 (MP 179.0) west of Cisco would likely also have to be restored to double track.) Improvements were completed on the Sierra grade in November 2009, including increasing of tunnel clearances in 15 restricted tunnels between Rocklin and Truckee and upgrading of signals to CTC, although the original Donner Pass grade (Track 1) was not restored. Since then trains of full-height or , double-stack container cars have run over Donner Pass; some tunnels on Track 2 between Bowman and Colfax were not enlarged, so stack trains in both directions must use the older, tunnel-free Track 1 between those points. Highways The Lincoln Highway, the first road across America, crosses Donner Pass; this was also a part of the Victory Highway. Interstate 80 was built through this area in the early 1960s. I-80 generally parallels the route of US 40 through the Sierra Nevada, but it crosses the Sierra crest at the Euer Saddle, about north of Donner Pass. Euer Saddle is referred to by CalTrans as "Donner Summit" at (), located on the south side of I-80 at the Castle Peak exit beyond Boreal Inn. Donner Summit is about higher than Donner Pass, but is wider and has a gentler approach that aided construction to Interstate Highway standards, which do not allow the sharp curves used by the Donner Pass Road. The grade is 3-6% for . The 1920s highway has been preserved as a scenic alternative to I-80. Weather Winter weather at Donner Pass can be brutal. Precipitation averages per year, and because California has a Mediterranean climate wherein most precipitation falls in the winter, much of it falls as snow. At an average of per year, Donner Pass is one of the snowiest places in the contiguous United States. Four times since 1880 total snowfall at Donner Summit has exceeded and topped in both 1938 and 1952. To take advantage of the heavy snows, the Boreal Ski Resort was built to the north. Ski resorts in the Lake Tahoe area report an average of of snowfall per season. Winds in the pass can also become extreme and wind gusts in excess of are common during winter storms. Winter temperatures in the area drop below