About 30 years ago, Timberline Models had an HO kit of an Idaho Springs mine, and I think it was just West of town. That is probably the one you are looking for. But it may be really hard to find now. Maybe somebody else has produced that kit after Timberline. I'm positive that there are some kits available of some structures in the Leadville area available.
Check out Caboose Hobbies website at
www.caboosehobbies.com, or call them, or any other fine dealers like Coronado for more information. The Gazette has lots of ads.
Mike
Now that I think about it, maybe that was 40 years ago.....
Good luck anyway.