Colorado · Area of Critical Environmental Concern
Castle Gardens ACEC
BLM found a natural system, a scenic value and a natural process here, and its plan calls for special management. BLM's records place no claim, lease or right of way inside the line today, and two grazing allotments cover part of it. It covers 310 acres and was designated January 18, 2024, in the 2024 Eastern Colorado 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
Ground: USGS The National Map, topographic tiles. Boundaries: BLM's own, read Oct 20, 2026. The 2 grazing allotments below aren't marked.Grazing allotments
2 grazing allotments cover part of this line. Their permittees aren't named here yet.
- BEAR CREEK3,772acres
- METHODIST MTN.3,399acres
The nearest areas
- Droney Gulch ACECColorado · 674 acres · 2 rights of way, 2 grazing allotments covering part of it8miles
- Ruby Mountain/Railroad Gulch ACECColorado · 1,772 acres · 5 rights of way, 6 grazing allotments covering part of it12miles
- Arkansas Canyonlands ACECColorado · 23,707 acres · at least 4 active mining claims, 8 rights of way, 12 grazing allotments covering part of it26miles
- Trickle Mountain ACECColorado · 43,857 acres · 4 rights of way, 13 grazing allotments covering part of it31miles
- Grape Creek ACECColorado · 16,558 acres · at least 59 active mining claims and 1 more BLM lists as Filed, 2 rights of way, 6 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 Castle Gardens 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