The Ciénega de Santa Clara is a 20,000-hectare brackish wetland on the east side of the delta of the Río Colorado in Sonora, México. It has developed as a result of the discharge of brine from the Wellton–Mohawk Irrigation District, in southwestern Arizona, through the Wellton–Mohawk Main Outlet Drain Extension, since 1977. The northern third of the ciénega is covered by dense cattails (Typha domingensis), Common Reed (Phragmites communis), and bulrush (Scirpus americanus). The southern two-thirds of the wetland consist of unvegetated evaporative saltflats (Glenn et al. 1992). The area is important for conservation, yet little effort has been devoted toward its birds. Investigations have focused mainly on its vegetated portion, which supports a large population of the endangered Yuma Clapper Rail (Rallus longirostris yumanensis; see Eddleman 1989) and of wintering waterfowl. The use of the saltflats by birds has been mostly overlooked. Only Eddleman (1989) has reported on the birds he recorded there, and none was a breeding Yuma Clapper Rail.