Nitrogen metabolism of elk (Cervus elaphus nelsoni) was investigated during 15 feeding trials of single- and multiple-component rations. Endogenous urinary nitrogen was 0.16 g N/$\text{Kg}^{0.75}$/day, metabolic fecal nitrogen was 5.58 g N/kg dry-matter intake, apparent nitrogen digestibility ranged from -99.9 to 88.0%, and true nitrogen digestibility was 98.0%. Feed nitrogen concentration was significantly related to fecal nitrogen content for phenolic-free rations. Ingested phenolics significantly increased fecal nitrogen excretion. Urea kinetic experiments were conducted in conjunction with 8 of the in vivo trials in which elk recycled 18-85% of the urea produced, which represented 23.9-198.0% of their dietary nitrogen intake. Biological value of dietary protein fell from 100 to 42% as dietary protein content increased from 5.6 to 29.3%. Digestible-energy intake necessary to maintain a positive nitrogen balance was 153 kcal/$\text{kb}^{0.75}$/day. Estimates of dry-matter intake needed to meet maintenance nitrogen requirements at varying dietary crude-protein concentrations are presented.