From the plaque:
This was the site of Sportsman's
Hall, also known as Twelve-Mile House, the hotel operated
in the latter 1850s and 1860s by John and James Blair.
A stopping place for stages and teams of the Comstock,
it became a relay station of the Central Overland Pony
Express. Here, at 7:40 a.m., April 4, 1860, pony rider
William (Sam) Hamilton rode in from Placerville and handed
the express mail to Warren Upson, who two minutes later
sped on his way eastward.
Plaque placed by the California State Park Commission in cooperation with the James W. Marshall Chapter No. 49, E. Clampus Vitus and the Central Overland Pony Express Trail Association, April 3, 1980.