Roughly 100 miles from you is my favorite 1000 yard range at Byers, CO
Colorado Rifle Club > Home
The Colorado Rifle Club holds 1000yd IBS matches and Highpower matches as well as some Black powder long range shooting. If you will be around next summer and are interested in trying 1000yd Benchrest let me know and I'll see if we can get something worked out.
You don't need to be a member to shoot at the matches.
There is also a 1000 yd range at the NRA Whittington Center in Raton, NM.
NRA Whittington Center - High Power Rifle Range