I just left the bird. It was perched in a tree along the ditch that borders the south east side of the large field across Prospect from the visitor center. Right where the road curves. A Great Horned Owl was roosting a couple hundred yards southwest of the hawk along the ditch.
The Harris's Hawk spent most of the time with both wings drooped open slightly (it didn't have a prey item), which was odd. It was facing west into the sun. Warming up? Looking big for the owl? Sick or injured? Whatever the reason, it's something to keep an eye on.
Good birding,
Paul Hurtado
Reno, NV (and Pueblo, CO)