The two areas of the dry, arid Great Basin that pioneers on the California Trail most dreaded were the Humboldt Sink and the waterless desert between the sink and the Truckee River, known as the 40 Mile Desert.
(From Interstate Highway 80 a few miles west of Lovelock, Nevada looking south: the creamy goo in the center of my photo of the Humboldt Sink stretches approximately 11 miles east to west and 4 miles north to south. One of many low mountain ranges of the Great Basin lies in the distance.)
Virginia Reed and her mother and siblings, still with the Donner Party, first arrived at the Humboldt Sink, where the Humboldt River literally disappears into the sand, leaving a gooey, sulphuric smelling surface of nearly 45 square miles. Unpleasant as it was, the party camped here because grass for their cattle grew nearby. The pioneers cut and gathered as much as possible in preparation to cross the 40 Mile Desert.
On the right: is what Virginia Reed saw when she started out–40 miles of sand and sagebrush with no river for relief. The eastern slope of the Sierra is in the distance.
This desert looked nothing like the Salt Desert that had cost the Donner Party so much, but it turned out to be just as deadly. More cattle, horses, and wagons were lost during their hurried crossing.
Fast-forward to today: a rest stop along Interstate 80 at the eastern end of the 40 Mile Desert boasts an impressive number of informative displays about the California Trail, its geology, and its pioneer history.
(Above, enjoying the informative displays and preparing to cross the 40 Mile Desert by air-conditioned automobile. Below, a display of the less fortunate crossing on foot.)