My biggest piece of advice for someone just graduating college is to find your Job FIRST before moving. Try getting on as intern in your Junior or Senior year with a company that is located here. There's a lot of Tech Jobs in Colorado Springs, Denver and Boulder. Colo Springs and Denver have a lot of Defense contracting jobs and despite the current climate the industry is pretty stable. There's also plenty of Petroleum industry jobs as well.
Denver is a great place for young people (affordable rent for a big city, lots of fit single girls, good nightlife etc.) and it's also the most moderate politically of the large cities in this state. Boulder is very leftist and liberal; while Colorado Springs is very conservative and right wing (Ward Churchill was a prof at CU Boulder while Focus on the Family is based in the Springs). Ft. Collins is a great city as well, I'm not positive on what the job climate is like up there as I'm in Defense and am unaware of what job opportunities are up there other than brewing (FTC is probably the most awesome beer city in the USA). The only turn off for me when it comes to FTC is that it's a much longer drive to get to the ski resorts.
I wouldn't worry too much about coming here and spending weeks to see if it's a good fit or not. When I was in High School in the mid 90s, going to CU Boulder was like a dream but they didn't have what I wanted to Major in, but 10 years later I got my first chance to visit Denver on a work trip and I was hooked. It took me about 6 years after that trip to finally get a transfer to move here. I lived and traveled all over the U.S. with the exception of the PNW and the only place that comes close to Colorado in terms of weather and recreation is California, but that place is completely outrageous in terms of cost of living.
As other people have pointed out in this thread WY and MT are "better" places than Colorado because they have fewer lefties and more wide open spaces, less traffic. cheaper housing etc. But finding an entry level engineering job with room for advancement will be harder to come by in those places unless you're out on the plains working in an oil field. Being out on the plains sucks and that's not why you wanna move here.