the ones i am aware of mostly are private clubs and so forth!

CRC (Colorado rifle club) 1000 in breyers very nice has Pits i shoot there often! in the summer

BCGC Buffalo Creek Gun Club up in bailey used to be an old army range up to 600 yards it is owned by the national forest service but leased out to that club also has pits.

wyoming has a few i know one club has a range with pits up to 600 yards+

also have herd the base up there has hosted matches and clinics before!

those are just the ones i can say i been too!