Montana · Area of Critical Environmental Concern
Woody Island
BLM found a natural system, a wildlife resource, a scenic value and a fish resource here, and its plan calls for special management. BLM's records place 1 right of way inside the line today, and 15 grazing allotments cover part of it. It covers 32,871 acres and was designated September 21, 2015, in the HiLine RMP (2015). 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
1 right of way sits inside the line.
- BIG FLAT ELECTRIC COOPERATIVE INC1right of way
Grazing allotments
15 grazing allotments cover part of this line. Their permittees aren't named here yet.
- Petrie Ranch18,934acres
- North Woody Island11,172acres
- HORSESHOE COULEE10,806acres
- SUNNYSLOPE9,850acres
- Cherry Ridge9,096acres
- Alkali Lake3,436acres
- Upper Woody Island2,555acres
- Customs1,957acres
- Silver Bow1,956acres
- BORDER1,852acres
- WEST SUNNYSLOPE1,445acres
- MID-SUNNYSLOPE1,279acres
- Anderson Ranch961acres
- CORNER801acres
- Lost Forty40acres
The nearest areas
- Malta GeologicMontana/Dakotas · 6,153 acres · 1 right of way, 4 grazing allotments covering part of it35miles
- Big Bend of the Milk RiverMontana/Dakotas · 1,992 acres · 1 right of way, 6 grazing allotments covering part of it44miles
- Frenchman BreaksMontana/Dakotas · 42,020 acres · 2 rights of way, 16 grazing allotments covering part of it51miles
- Zortman/Landusky Mine ReclamationMontana/Dakotas · 2,686 acres · at least 4 active mining claims, 17 rights of way, 2 grazing allotments covering part of it72miles
- Azure CaveMontana/Dakotas · 143 acres · a grazing allotment covering part of it74miles
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 Woody Island. 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