Jackrabbits are cyclic. They increase in numbers and then crash. You probably were there a year after the crash. They rebuild the population quickly. When the population is strong you can kick out over 100 in a day of walking the sagebrush. Lot of fun rolling them with a 22. When I was growing up in CO there was no closed season or bag limit on than and I used to go out and shoot them with my 7mm Mag after letting them get out at least 100 yards. If you can hit jackrabbits on the run with your deer rifle then hitting deer becomes easy. I also used to go up into the high country to shoot marmots with my 7mm. I'd only shoot them at ranges over 300 yards. Made long shots on deer and elk easy.

But that was back in my misbegotten cowboy youth growing up in CO before the state got ruined by liberal transplants from CA. If you tried that stuff now they would probably get their panties in a twist despite it being legal.