Nevada · Area of Critical Environmental Concern
Timber Mountain Caldera
BLM found a natural process here, and its plan calls for special management. BLM's records place 1 right of way inside the line today. It covers 244,835 acres and was designated February 26, 1992, in the Nellis Test and Training Range 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
1 right of way sits inside the line. BLM files 1 under non-energy facilities.
- Holder not listed by BLM1right of way
The nearest areas
- Big DuneNevada · 1,900 acres · nothing placed inside33miles
- Amargosa MesquiteNevada · 6,784 acres · at least 10 active mining claims47miles
- Ash MeadowsNevada · 37,280 acres · at least 43 active mining claims, 5 rights of way48miles
- Amargosa NorthCalifornia · 124,317 acres · at least 65 active mining claims, 10 rights of way56miles
- Shooting GalleryNevada · 15,603 acres · 1 right of way, 4 grazing allotments covering part of it67miles
More from BLM's Nevada office
Every area BLM's Nevada 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 Timber Mountain Caldera. 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