I guess you've never been through DFW before? Yes you will most likely change terminals at DFW, but even changing terminals no gate is further than 15 minutes from another gate unless the SkyLink is down - and I walk slow. The flights to/from GJT will most likely be out of terminal B, although there are some regional jets that use D or E. Mainline could be A, C, or D. Either way with a 60 minute connection you should have plenty of time.