Imperial National Wildlife Refuge protects wildlife habitat along 30 miles of the lower Colorado River in Arizona and California, including the last unchannelized section before the river enters Mexico. The river and its associated backwater lakes and wetlands are a green oasis, contrasting with the surrounding desert mountains. Wetland wildlife is most abundant in winter, when ‘snowbirds’ such as cinnamon teal and northern pintail use the refuge. During the summer months, look for permanent residents such as great egrets and muskrat. In the desert, wildlife such as black-tailed jackrabbits and western whiptail lizards are plentiful. Watch at dawn and dusk for desert bighorn sheep and mule deer heading to the river for a drink.