In Oregon, sage grouse (Centrocercus urophasianus) were common in the eastern portion of the state. Since 1940 populations declined because of decreased productivity. The western subspecies (C. u. phaios) was listed as a candidate for threatened and endangered status in 1985 because of declines in Oregon and Washington and extirpation from British Columbia. Habitat availability and habitat condition were factors associated with impaired productivity. Stand structure and forb availability were characteristics most associated with habitat selection by hens with broods. The objectives of this study were to determine habitat use and selection by hens with broods and the relationship between food availability, habitat use by hens, and diets of juvenile sage grouse. Of the 2 study areas used, Hart Mountain had greater long term productivity and abundance than Jackass Creek. Use of cover types and habitat components were compared within and between study areas. In this study, sage grouse hens selected low sagebrush (Artemisia sp.) cover types during early brood-rearing then switched to use of big sagebrush cover types during late brood-rearing. In general, cover types used selectively had greater availability of forbs, and changes in forb availability within cover types from early to late brood-rearing corresponded to changes in cover type use. Differences in forb availability between study areas may have affected productivity. Hens at Jackass Creek selected sites with forb cover similar to that available to broods at Hart Mountain and home ranges were larger at Jackass Creek. Furthermore, diets of juvenile sage grouse were higher in forbs and insects at Hart Mountain. Larger home ranges and less nutritious diets were potentially responsible for lower productivity at Jackass Creek. Results indicated that management to improve brood habitat should focus on maintenance of cover type diversity and availability of forbs. / Graduation date: 1993