It was on July 7th, 1919 that The Army's Motor Transport Corps convoy left Washington DC headed towards San Francisco. The trip was to see if the military could move men and machines across the country using the recently "completed" Lincoln Highway as the route. They almost didn't make it, arriving in Oakland seven day's behind schedule.
The convoy included, "24 expeditionary officers, 15 War Department staff observation officers, including a young, Bvt Lt Col Dwight D. Eisenhower of the Tank Corps, and 258 enlisted men." The experience Eisenhower had on the trip helped formulate his plan as President for an Interstate Highway System, still in place today.
The National Archives has a video of some of the trip. It's fascinating to watch, and at the 18:47 mark we start to see the mountains of Nevada and California, and the climb up Meyers Grade, across the summit, and down into Kyburz at the 21:45 mark.