We used habitat-selection data from a reintroduced population of elk (Cervus elaphus) in northeastern Nevada, USA, to develop a resource-selection function to adjust nutritional carrying capacity estimates. Constrained estimates provide population levels that minimize overuse of key foraging communities. We estimated economic nutritional carrying capacity (I_NCC) for 236-kg lactating cow elk in autumn 1999 and 2000 to reflect expected animal performance under maintenance (2,550 kcal/kg DM) and good (2,750 kcal/kg DM) levels of standing digestible energy. We used our resource-selection function to redistribute I_NCC densities (RSFD) for aspen (Populus tremuloides), conifer, curl-leaf mountain mahogany (Cercocarpus ledifolius), sagebrush (Artemisia spp.)–herb, and snowbrush ceanothus (Ceanothus velutinus) cover types across the summer range and then adjusted original I_NCC estimates according to these RSFD when expected densities exceeded original I_NCC estimates. Maintenance performance I_NCC estimates were 2,533 cow elk (95% CI: 1,327–3,739) in 1999 and 1,655 (95% CI: 886–2,424) in 2000. Good performance I_NCC estimates were 2,264 cow elk (95% CI: 1,150–3,378) in 1999 and 1,100 (95% CI: 384–1,816) in 2000. The best habitat model provided evidence that forage availability and distance to water influenced habitat selection. Adjustments in I_NCC for 1999 and 2000 and at both performance levels corresponded to decreases of 18–35% in original I_NCC estimates. Decreases were attributed to more cow elk predicted by RSFD to be in aspen, conifer, and sagebrush–herb cover types than predicted by I_NCC. Each year, RSFD predicted that fewer elk would use mahogany and snowbrush cover types than original I_NCC models. The adjusted carrying capacity estimates provided population levels that should avoid appreciable alteration of aspen, conifer, and sagebrush–herb communities while ensuring nutritious resources during lean periods. Our paper provides a critical refinement for nutritional carrying capacity models through incorporating prediction of animal selection of nutritional resources.