Bighorn-Horsethief Survey Project
NRMG Project · Since 2021
Bighorn–Horsethief Survey Project
Remapping Montana's longest cave system from scratch, with modern instruments and a lot of help from the grotto.
Last updated: 7 August 2026
Overview
What we're doing
The Bighorn–Horsethief cave system is one of the most significant caves in the region. Past surveys put it at 14.615 miles on the NSS U.S. Long Caves list. That work was done across the 1970s and 80s by a handful of different grottos, with analog instruments — and a significant amount of the original data has since been lost. The maps that have survived are generalized in places and missing passages in others.
Our goal is to remap the entire system with modern tools — DistoX2 laser rangefinders, and a planned run with LIDAR — and produce one complete, clean map from end to end.
The project is open to cavers at every experience level. If you've never surveyed before, we'll train you on your first couple of trips out; if you're experienced, it's a good way to keep your skills sharp. Training sessions cover vertical technique, survey instrumentation, sketching, and cave conservation.
Resources
Helpful links
Email list
Join the bhhtsurvey Google Group
Trip announcements, sign-ups, and project-wide discussion.
Read first
Project orientation
Standards and general info for survey trips.
Archive
Project Google Drive
All project documents, data, and references.
Learn
How cave surveying works
Derek Bristol's overview. New to it? We'll train you in the field.
Schedule
2026 project weekends
The schedule below was announced by Katey Bender (Communications/Cartography) in March. Sign-ups typically open about a month ahead of each trip; watch the bhhtsurvey Google Group and the NRMG events calendar.
April
April 25–26
2-day setup weekend
May
May 23–25
Memorial Day weekend
June
June 19–21
August
August 9–16
Week-long trip · Steve Zeman cooking
September
September 5–7
October
October 10–12
Tentative
No July weekend — that slot is folded into the August week. New to surveying? Show up anyway; your first couple of trips are also training trips.
Support the project
Donate
Ropes, batteries, permits, printing, LIDAR time, and camp repairs at the armpit complex — every trip has a gear bill. Donations go directly to project costs.
Who's driving it
Project leaders
The Northern Rocky Mountain Grotto sponsors this effort. Leadership refreshed in February 2026. Click a name to see contact info. Other local grottos are encouraged to join in.
Project Lead ▾
Dan Austin
Joined as lead Feb 2026. Long list of survey projects out of South Dakota.
Email: hillscaver [at] gmail [dot] com
Best for: project direction, trip planning, new staff interest.
Gear, Logistics & Camp ▾
Will Boekel
Founded the project in 2021. Now runs camp, gear, and on-the-ground logistics.
Email: wboekel [at] nrmg [dot] org
Best for: gear kits, camp repairs at the armpit complex, logistics.
Communications & Cartography ▾
Katey Bender
Trip sign-ups, project announcements, and cartography work.
Email: katey.e.bender [at] gmail [dot] com
Best for: sign-up questions, trip reports, map requests.
Permitting ▾
Jason Forberg
Land-manager coordination and permits.
Email: k2climber02 [at] hotmail [dot] com
Best for: access questions, land-use issues.
3D LIDAR scanning
Open position
Have LIDAR experience or gear? Reach out to Dan or use the contact page.
From the field
Comments
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