Wyoming · Area of Critical Environmental Concern
Paleocene, Eocene Thermal Maximum (PETM) 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 2 oil and gas leases and 1 right of way inside the line today, and nine grazing allotments cover part of it. It covers 14,927 acres and was designated September 21, 2015, in the Cody 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. BLM files 1 under non-energy facilities.
- WYOMING STATE - DEPARTMENT OF TRANSPORTATION1right of way
The oil and gas leases
2 active oil and gas leases sit inside the line. 0 of them took effect before the area was designated on September 21, 2015.
- LIBERTY PETROLEUM CORPORATION2leases
Grazing allotments
9 grazing allotments cover part of this line. Their permittees aren't named here yet.
- Sand Draw59,674acres
- Thumper47,337acres
- Foster Gulch35,940acres
- Badlands21,910acres
- Clarksfork20,721acres
- Sage Creek Group12,227acres
- Big Trap10,652acres
- Chapman Bench 10807,279acres
- Corbett Dam4,497acres
The nearest areas
- Clark's Fork Canyon ACECWyoming · 4,714 acres · 6 grazing allotments covering part of it23miles
- Petroglyph CanyonMontana/Dakotas · 239 acres · 2 grazing allotments covering part of it25miles
- Weatherman DrawMontana/Dakotas · 12,282 acres · 2 rights of way, 5 grazing allotments covering part of it26miles
- Pryor FoothillsMontana/Dakotas · 2,606 acres · 3 grazing allotments covering part of it27miles
- Grove CreekMontana/Dakotas · 8,252 acres · 3 rights of way, 3 grazing allotments covering part of it28miles
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 Paleocene, Eocene Thermal Maximum (PETM) 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