We used a motion-triggered camera to document and qualify the nature of interspecific interactions between elk (Cervus elaphus) and feral horses (Equus caballus) at an isolated, natural water source in Mesa Verde National Park, Colorado. The camera was active for at least 110 of 145 potential trap-nights between 24 April 2012 and 16 September 2012. Elk and horse interactions were observed 51 times, and elk were averted from accessing water 42 times (82%). Feral horses exhibited dominant behavior over native elk during the driest time of the year (May–June), often preventing acquisition of water by elk.