Colorado · Area of Critical Environmental Concern
Sapinero Mesa ACEC
BLM found a wildlife resource and a natural process here, and its plan calls for special management. BLM's records place at least 39 active mining claims and 2 rights of way inside the line today, and five grazing allotments cover part of it. It covers 17,242 acres and was designated October 17, 2024, in the 2024 Gunnison Sage-Grouse RMP Amendment. In the plan's name, RMP stands 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 39 claims sit inside this line: 39 active, 39 with a holder BLM names. BLM lists 39 as Active.
- FERMI METALS LLC39claims
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
2 rights of way sit inside the line. BLM files 2 under non-energy facilities.
- GUNNISON COUNTY COMM1right of way
- Holder not listed by BLM1right of way
Grazing allotments
5 grazing allotments cover part of this line. Their permittees aren't named here yet.
- Powderhorn Com57,620acres
- Sapinero Mesa32,052acres
- Goose Cr3,114acres
- Big Willow2,943acres
- Little Willow2,437acres
The nearest areas
- Dillon Pinnacles ACECColorado · 940 acres · nothing placed inside8miles
- West Antelope Creek ACECColorado · 29,045 acres · 11 rights of way, 7 grazing allotments covering part of it10miles
- South Beaver Creek ACECColorado · 4,545 acres · 1 right of way, 2 grazing allotments covering part of it14miles
- Chance Gulch ACECColorado · 13,804 acres · at least 3 active mining claims, 6 rights of way, 3 grazing allotments covering part of it19miles
- Slumgullion Earthflow ACECColorado · 1,317 acres · 5 rights of way, 3 grazing allotments covering part of it28miles
More from BLM's Colorado office
Every area BLM's Colorado 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 Sapinero Mesa ACEC. 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