Rye Patch State Recreation Area occupies a watery oasis along the Humboldt River in otherwise arid country, shaped by layers of history far older than its modern reservoir. Prehistoric Lake Lahontan once covered this region, and after its retreat, animals and people used the river corridor for thousands of years, leaving fossils and archaeological evidence nearby. In the mid-nineteenth century, the rye-covered meadows here served overland emigrants during the California Gold Rush, including travelers taking the Applegate-Lassen Cut-Off. The area took its modern form when Rye Patch Dam, built from 1933 to 1936 as a Public Works Administration relief project, created the reservoir that now anchors recreation.