Montana · Area of Critical Environmental Concern
East Pryor Mountain
BLM found a natural system, a wildlife resource, a cultural value and a historic value here, and its plan calls for special management. BLM's records place at least 24 active mining claims and 3 rights of way inside the line today, and four grazing allotments cover part of it. It covers 11,061 acres and was designated September 21, 2015, in the Billings and Pompeys Pillar NM RMP (2015). In the plan's name, NM stands for National Monument and RMP for resource management plan.
One of the 1,120 places the Bureau of Land Management has designated an Area of Critical Environmental Concern. This page shows its line, what BLM found there and what sits inside it.
The line
Who holds the claims
At least 24 claims sit inside this line: 24 active, 23 with a holder BLM names and 1 with a claimant BLM withholds under the Privacy Act. BLM lists 24 as Active.
- BBL-2 LLC23claims
- Names withheld by BLM (private individuals)1claim
BLM's mining rules list designated ACECs among the places where mining that disturbs the surface beyond casual use needs a plan of operations BLM approves. Exploration of five acres or less can go ahead on a notice instead.
The rights of way
3 rights of way sit inside the line. BLM files 3 under non-energy facilities.
- Holder not listed by BLM1right of way
- US WEST COM INC1right of way
- TCT WEST INC1right of way
Grazing allotments
4 grazing allotments cover part of this line. Their permittees aren't named here yet.
- PMWH23,286acres
- Gyp Springs20,826acres
- Deadman10,086acres
- Crooked Creek11,510acres
The nearest areas
- Pryor FoothillsMontana/Dakotas · 2,606 acres · 3 grazing allotments covering part of it6miles
- Petroglyph CanyonMontana/Dakotas · 239 acres · 2 grazing allotments covering part of it9miles
- Little Mountain ACECWyoming · 21,443 acres · 1 right of way, 6 grazing allotments covering part of it14miles
- Weatherman DrawMontana/Dakotas · 12,282 acres · 2 rights of way, 5 grazing allotments covering part of it24miles
- Five Springs Falls ACECWyoming · 160 acres · 2 rights of way, 2 grazing allotments covering part of it24miles
More from BLM's Montana/Dakotas office
Every area BLM's Montana/Dakotas office holdsThe proposed rule
A proposed rule, RIN 1004-AF53, would change how BLM drafts every land use plan, and how it designates ACECs like East Pryor Mountain. The comment window hasn't opened: the proposed rule wasn't in the Federal Register at our last check. The Watch sends one email the day it prints.
The rule's abstract
The purpose of this rulemaking is to establish in regulations an updated process for the approval of the development, revision, amendment, and maintenance of land use plans, as provided for by the Federal Land Policy and Management Act of 1976, for public lands administered by the Bureau of Land Management (BLM). Additionally, this rulemaking will provide clarification of the process the BLM uses for designating Areas of Critical Environmental Concern.Unified Agenda entry for RIN 1004-AF53, Publication ID 2026, reginfo.gov (OMB OIRA), read Oct 18, 2026