Wyoming · Area of Critical Environmental Concern
Green Mountain ACEC
BLM found a wildlife resource and a cultural value here, and its plan calls for special management. BLM's records place at least 571 active mining claims (and 80 more BLM lists as Filed), 18 oil and gas leases and 2 rights of way inside the line today, and six grazing allotments cover part of it. It covers 24,924 acres and was designated June 26, 2014, in the Lander 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 651 claims sit inside this line: 571 active and 80 filed and pending, 651 with a holder BLM names. BLM lists 571 as Active and 80 as Filed. The index's own placement puts 681 claims inside this line. Ours finds 651.
- Sweetwater Uranium Inc631claims
- LOGRAY MINERALS LLC16claims
- Branka Minerals LLC4claims
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.
- WYOMING STATE OFFICE2rights of way
The oil and gas leases
18 active oil and gas leases sit inside the line. 8 of them took effect before the area was designated on June 26, 2014.
- BRO ENERGY LLC7leases
- INTERNATIONAL PETROLEUM LLC6leases
- Holder not listed by BLM4leases
- JOEMAR WYOMING OPERATING LLC1lease
Not counted: 1 more lease BLM lists as Interim.
Grazing allotments
6 grazing allotments cover part of this line. Their permittees aren't named here yet.
- ARAPAHOE CREEK258,718acres
- WHISKEY PEAK INCOMM73,151acres
- MOUNTAIN36,301acres
- FENCED ALLOTMENT12,945acres
- ALMA GRIEVE PASTURE4,701acres
- DIAMOND HOOK605acres
The nearest areas
- Blowout Penstemon ACECWyoming · 29,151 acres · at least 96 mining claims BLM lists as Filed, 1 oil and gas lease, 4 rights of way, 7 grazing allotments covering part of it32miles
- Beaver Rim ACECWyoming · 6,729 acres · 5 rights of way, 4 grazing allotments covering part of it35miles
- Twin Creek ACECWyoming · 65,109 acres · at least 1 active mining claim and 1 more BLM lists as Filed, 1 oil and gas lease, 22 rights of way, 22 grazing allotments covering part of it48miles
- South Pass Historical Landscape ACECWyoming · 158,545 acres · at least 485 active mining claims and 942 more BLM lists as Filed or Under Review, 50 rights of way, 20 grazing allotments covering part of it50miles
- Alcova Fossil Area ACECWyoming · 5,977 acres · 3 rights of way, 3 grazing allotments covering part of it50miles
More from BLM's Wyoming office
Every area BLM's Wyoming 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 Green Mountain 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