Throughout this trip to Yellowstone, we photographed extensively in the Lamar Valley, a high plateau and biodiverse region in northern Yellowstone National Park, where if you are lucky you can see wolves, coyotes, long horn sheep, mountain goats (way far off), antelope, bears and all sorts of wildlife. The "sweet" spot was a two hour drive over mountains from where we were staying and more than once we made the trip twice in a day, both before dawn and after sun down. While getting ready to leave a spot where we were observing wolves and coyotes hovering around a dead bison, we were passed by an antelope that blew past us at full speed of maybe 40mph. We snapped a few shots but were more than anything dumb founded. Good thing Jeff, a very experienced nature photographer who knows this are intimately (redcliffsphotography.com) was driving. He immediately accelerated to 60mph to catch up then matched the antelope for speed. The two of us on the right side kept shooting and adjusting our cameras on the fly in the hope of getting at least one in focus, frozen or panned shot while the long lenses on our cameras bounced all over the place and we tried to steady them. Here is one of my favorites. 1/1000 sec, f 5.6, ISO 200, 500MM.