Another fairly common mammal of Yellowstone National Park is the Pronghorn. This animal is often called a "Pronghorn Antelope" (including by me, up until I wrote this blog post), but according to Wikipedia, it is not really an antelope at all.
One afternoon, Tammy and I decided to hike a trail that started in the Yellowstone Picnic Area (in the northeast corner of the park), and paralleled the Yellowstone River Canyon for a couple of miles. It was a beautiful hike, even though I was not exceptionally comfortable hiking along a nearly 500 foot drop. I personally decided that a new trail, about 5 feet further away from the canyon, but otherwise exactly parallel to the existing trail, would be better suited for my needs. When we got to the point where trail headed away from the canyon, however, we had beautiful views of a shallower section of the canyon, known as Bannock Ford, part of the Bannock Trail (photo #1).
After we turned away from the canyon and began the second half of the loop, we came across three Pronghorn that were chilling out in the meadow. We spooked them, but they did not just run away (photos #2 and #3). They acted nervous, and the male of the bunch kept making this sneezing noise, something that Tammy and I both interpreted as "don't come any closer". We obliged, and simply took photos until the Pronghorn moved away from the trail.