The United States Congress designated the Imperial Refuge Wilderness (map
) in 1990 and it now has a total of 15,056 acres
It is managed by the Fish and Wildlife Service.
The Imperial Refuge Wilderness is bordered by
the Indian Pass Wilderness
to the west, the Little Picacho Wilderness
to the south, and the Trigo Mountain Wilderness
to the east.
You might be surprised to find a lush river ecosystem in the midst of the Sonoran Desert, the hottest and driest in the United States, a land of prickly cacti and specially adapted plants and animals. But that's exactly what you get in this Wilderness. The lower Colorado River, the boundary between California and Arizona, has many backwater lakes varying in size from one-half acre to 700 acres. Here, in 1941, the Imperial National Wildlife Refuge was established to preserve all forms of life found in the lower Colorado River region. The 25,125 acres of the refuge stretch along 30 miles on both sides of the river in Arizona and California. A portion of the refuge in Arizona was designated Wilderness in 1990, followed by a piece of the California side.
When enough rain falls the desert bursts into stunning bloom: yellow paloverde, lavender smoke trees and ironwood, pink beavertails, red prickly pears, and purple and gold bellyflowers (so named because you must lie on your belly to appreciate these small blossoms). Mule deer come to drink from the river beside great blue herons while desert bighorn sheep watch from multihued hills nearby. Gambel's quail are ubiquitous, and wild burros can be seen from time to time. Resident and migratory birds are abundant. Beavers inhabit the waters, which may contain a few of the endangered Colorado squawfish--sometimes known to reach five feet in length.
Backwater lakes attract anglers who fish, typically with great success, for largemouth and striped bass. With a canoe you can put in at the upper boundary for easy paddling down to Martinez Lake Marina at the lower end. Because no overnight camping is allowed on the refuge, you'll have to camp at Picacho State Recreation Area on the California side. Hikers who wander into the Wilderness must carry plenty of water, a map, and a compass; each year, a few careless visitors get into jams that result in costly search-and-rescue operations.