The 4,351-acre Chesaw unit is in northwest Okanogan County, some four miles south of the Canadian border, about 20 miles east of Oroville. Elevations range from near 3,200 to 4,200 feet. The major habitat type is shrub steppe, with patches of conifers at higher elevations. Mary Ann Creek is a perennial stream that flows through in a southerly direction, with many active and remnant beaver dams. The creek�s flood plain is fairly wide in some areas and riparian vegetation flourishes there and along the stream channel. There are several lakes and man-made ponds, and one of the larger of the unit�s several springs is used as the source of potable water. Chesaw has one sharp-tailed grouse lek site. It also supports mule and white-tailed deer, various upland game birds, bald and golden eagles, peregrine and prairie falcons, northern goshawks, Lewis woodpeckers, and loggerhead shrikes.