Everyone I know in Colorado is nuts about hiking, hunting, fishing, camping. It's just deeply ingrained into the culture there in a way I don't usually hear about for entire states.

I've heard it said that the weather is a big part of it because, most of the year, it stays well inside the ranges of temperature where you can day hike/ride in regular clothing. No need for cold weather gear. Since there's supposedly also a ton of wild space that's pretty compared to neighboring states, it adds up.

Again, this is all second or third hand

Colorado is having a population boom iirc and my theory is that it mainly attracts rich outdoorsy types.