From the plaque:
This popular resort and stopping
place for stages and teams of the Comstock, established
by Swift and Watson in 1856, became a remount station
of the Central Overland Pony Express. Here on April 4,
1860, Division Superintendent Bolivar Roberts waited with
a string of mules to help pony rider Warren Upson through
the snowstorm on Echo Summit.
Plaque placed by the California State Park Commission in cooperation with the Highway 50 Association, and the Central Overland Pony Express Trail Association. April 3, 1960.