I spent a while watching this band of wild horses from a distance and they seemed at ease. All of a sudden they ran down this section of cliff, parts of which were fairly steep. I couldn't see at first what the horses were alarmed about. They stood, staring, for a few moments and then ran back up the cliff, some of them choosing even steeper sections, before running over the top and disappearing. A few moments after that, a huge, lumbering bull bison rounded the corner.
Theodore Roosevelt National Park
Wild MustangsWild HorsesherdTheodore Roosevelt National ParkNorth Dakota