Definitely go for it- you could always go the grad school route after a year or two if you can't find a decent job.
I've got some friends that moved out here post college. I'd recommend moving to either an area with lots of young people (college students, recent grads- Boulder, Golden, LoDo, Durango) or a mountain town/western slop so that you could have a lot of fun and be close to the mountains. If you've lived for a while in rural PA, you could handle rural CO.
Don't underestimate the awesomeness of the western slope/mountain areas- before moving, you should look for a real job in Durango, Gunnison, Mesa, Steamboat, Craig, Grand Junction, etc for the heck of it. There might be some decent geology jobs to be found out on the western slope because of the mining/oil/natural gas industry out there, and as oil prices rise this summer some more jobs might pop up. It didn't cross my mind post graduation to check out Grand Junction/Mesa, but after a friend moved out there and I checked it out, if I could make decent money living in GJ or Mesa I'd move there from Boulder for sure.
Good luck! Make it happen- you can do it!