Where do full timers go out west to escape the heat?

Ok... We are not full timers but thought this might be a good place to post our question. We are actually snowbirds but have sold our house in Colorado and are moving to Arizona. So, we will be leaving the summer heat for at least 4 months a year. As 40 year residents of Colorado, we know where to escape the summer heat in Colorado such as Buena Vista, Ouray, Silverton and Lake City. Looking for advice of places out west to go to.

We have a Jeep, ATV and our feet to explore back country places. Some very limited boondocking is ok. Really want to stay away from places like the Tetons, Yellowstone and Glacier National Parks. Have explored around Lander, Cody and Dubois Wyoming. We are virgins to Oregon, Washington, Idaho and most of Montana. Might want to stay up to a month in a single place.

Thanks in advance! Private messages welcome.