Colorado · Area of Critical Environmental Concern
Slumgullion Earthflow ACEC
BLM found a natural system here, and its plan calls for special management. BLM's records place 5 rights of way inside the line today, and three grazing allotments cover part of it. It covers 1,317 acres and was designated February 5, 1993, in the 1993 Gunnison Resource Area RMP. 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
The rights of way
5 rights of way sit inside the line. BLM files 4 under non-energy facilities and 1 under fiber optic facilities.
- Holder not listed by BLM3rights of way
- HINSDALE COUNTY (Colorado)2rights of way
Grazing allotments
3 grazing allotments cover part of this line. Their permittees aren't named here yet.
- Allotment USFS-GRZ-10340.01043115,570acres
- Allotment USFS-GRZ-10336.01043115,362acres
- Slumgullion3,722acres
The nearest areas
- Redcloud Peak ACECColorado · 6,093 acres · 3 grazing allotments covering part of it8miles
- American Basin ACECColorado · 1,605 acres · at least 1 active mining claim, a grazing allotment covering part of it14miles
- Sapinero Mesa ACECColorado · 17,242 acres · at least 39 active mining claims, 2 rights of way, 5 grazing allotments covering part of it28miles
- Dillon Pinnacles ACECColorado · 940 acres · nothing placed inside35miles
- South Beaver Creek ACECColorado · 4,545 acres · 1 right of way, 2 grazing allotments covering part of it36miles
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 Slumgullion Earthflow 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