Daily travel of protein supplemented and non-supplemented lactating and non-lactating mature (>4 years of age) Santa Gertrudis X Hereford and Hereford X Santa Gertrudis crossbred cows was estimated between 29 May and 18 August 1986. The study was conducted on semidesert rangeland in south-central New Mexico. Ambient air temperatures ranged between 7 and 38°C. Relative humidity ranged between 15 and 91%, with precipitation 49% above the long-term January–August mean of 147 mm. Four lactating and 4 non-lactating cows were fed an average of 1.4 kg per head day⁻¹ of a 41% crude protein cottonseed supplement every 3.5 days. Ten similar non-supplemented cows, 5 lactating and 5 non-lactating, were grazed with the supplemented animals in paddocks averaging >2000 ha in size. To monitor travel, the 18 cows were each bi-pedometered with digital pedometers attached to their front legs.