History & Natural History – Donner Memorial State Park


It’s the dark side of the California dream, one of the most gruesome stories of the Old West: The Donner Party.

In April 1846, a group of midwestern families left Independence, Missouri, bound for California. Their wagon train rolled over the Great Plains and through the Rockies, but was seriously delayed when a “shortcut” leading southwest was anything but. A breakdown in civilized behavior followed: the emigrants quarreled constantly; one man killed another; an old man was left on the trail to die.

An early and severe snowstorm that prevented passage over the High Sierra forced the ill-fated party to spend the winter near present-day Truckee. Forty-one of the 89 would-be settlers perished. When their provisions and oxen were consumed, the desperate emigrants finally cannibalized their dead friends and relatives.

Today, Donner Memorial State Park is located where many members of the Donner Party spent their final days. Rangers report that about two hundred thousand visitors, most very curious about the cannibalism aspect of the Donner story, stop at the state park each year.

Outside the park visitor center is the tall Pioneer Monument; its base measures 22 feet high, the height of the snow during that terrible winter of 1846-47. Inside the park visitor center is the Emigrant Trail Museum, which depicts the demise of the Donner Party, plus more positive aspects of the region’s history.

Natural History

The museum offers a good introduction to the natural history of the Sierra Nevada.

To see some of this natural history for yourself, take a hike. One of the most dramatic (and obvious) workings of nature is the evidence left behind of recent glaciation. The great sheet of ice that slid through the region thousands of years ago left behind huge boulders and other rock debris.

The forest surrounding Donner Memorial State park is made up primarily of Lodge Pole pine, Jeffrey pine and White Fir. Because we’re at nearly 6,000 feet in elevation, there is no poison oak. You may see deer, squirrels, chipmunks, porcupines, raccoons, beavers and a wide variety of birds while visiting.

In and near the park are fascinating traces of the geologic process that shaped this portion of the Sierra Nevada. Rounded, smooth-surfaced rock outcrops are the result of giant bubbles of molten rock that cooled and hardened as they rose up into the earth’s surface (called “granitic intrusions). More recently, erosion has exposed that granite bedrock. The Sierra’s steep eastern face, which was such a formidable barrier for the Donner Party and other California immigrants, was formed over the last few million years by the tilting up of a gigantic section of the earth’s crust. The huge granite block tipped up dramatically on the east and tipped down on the west to disappear beneath the accumulated sediments that form the Sacramento Valley. Throughout much of the last million years, glaciers dominated the crest of the Sierra Nevada. One of them carved out the Truckee Basin, where the park is located, depositing gravel and some huge boulders in what is now a thickly forested area. When the glacier retreated, it left behind a terminal moraine of loose soil and gravel that blocked the creek channel and resulted in the formation of Donner Lake.