With more than 3000 acres of hiking, camping, water activities, cross country skiing and snowshoeing in season, and sheer outdoor splendor, Donner Memorial State Park also maintains a museum and monument to honor past explorers of this landscape, including the tragically famous Donner party. Other exhibits pay tribute to the Native Americans of the region and the Chinese builders of the railroad.
If you go:
Be sure to visit the sites of two pioneer cabins, the Murphy and Schallenberger sites. The park is open sunrise to sunset and the visitor center is open 10 to 5 every day except major holidays. Camping during the summer months only. The temperature, of course, can get very chilly, even during the summer.
Links:

12593 Donner Pass Road
Truckee, California 96161 USA
donnermuseum@parks.ca.gov
Mailing address:
P.O. Box 942896
Sacramento, CA 94296 USA
Phone Numbers:
Visitor Center
+1 (530) 582-7892
+1 (530) 582-7892
Entrance Kiosk
+1 (530) 582-7894
+1 (530) 582-7894