Park Service Land
A number of national parks and monuments offer winter-camping opportunities. Organ Pipe National Monument is a sprawling wilderness exemplifying the botanically diverse Sonoran Desert, a place of ragged mountains and saguaro flats. Its Twin Peaks Campground offers more than 200 campsites, including some accommodations for RVs. Quieter and more removed is the four-site Alamo Campground, devoted to tent camping. As of November 2010, backcountry camping in Organ Pipe was closed; check with the park for updates on this restriction. Another possible option is camping in Saguaro National Park's Saguaro Wilderness Area, which includes six designated campgrounds. These relatively high-elevation areas may experience chilly temperatures, depending on the weather pattern.
State Parks
A number of state parks in western and southern Arizona offer generally comfortable winter camping. These include Patagonia Lake State Park along a reservoir of Sonoita Creek, with wildlife-rich riparian thickets and plenty of fishing opportunities. Another resevoir park, Alamo Lake, set at the confluence of the Big Sandy and Santa Maria rivers, is often a good choice, too. The park is renowned both for its fishing---bass, bluegill, catfish and crappie are common---and for night-sky viewing.
Other Options
Like many western states, Arizona has a great deal of federal acreage managed by the Bureau of Land Management. Dispersed camping opportunities are usually plentiful, except in areas with special restrictions. Painted Rock Petroglyph Site, about 26 miles west of Gila Bend, has a primitive camping area in addition to its impressive collection of ancient rock art. The Bureau of Land Management notes that temperatures in the winter may swing from freezing lows to 80 degree highs. Most visitors to the site come between autumn and spring. Dispersed camping is also possible in the Ironwood Forest National Monument, where scrub woodlands of saguaro, ironwood, mesquite and other species blanket desert basins broken by stony mountain ranges.