I can't help you on where to go but just remember that the prairie rattlesnake is considered a small game animal and you need a license to hunt them and there is only a 2 month season to hunt along with a bag and possession limit.
Critter is right, there is a season and bag limit. I don't know the details, but you can find out easily enough on the Colorado Parks and Wildlife website. There are tons of rattlesnakes in the northwest corner of the state. Find a little water with rocks nearby and you'll be lucky not to step on one. Don't look at the highest elevations.
Being a bowhunting I've always been fanatical about scent control. Whether it's sprays, carbon clothing etc. I've tried it. The best thing that I have found for eliminating human scent is Betadine. It's been used in hospitals and homes for decades as a defense against infections on minor scrapes and burns. It can typically be found near the pharmacy in any of the major "one stop shop" stores, and a bottle will last multiple hunting seasons.
Before every hunt possible I...