California · Area of Critical Environmental Concern
Big Marias
BLM found a wildlife resource and a cultural value here, and its plan calls for special management. BLM's records place 25 rights of way inside the line today. It covers 4,485 acres in California, managed by BLM's Arizona office, and was designated January 29, 2010, in the Yuma 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
25 rights of way sit inside the line. BLM files 22 under non-energy facilities and 3 under other energy facilities.
- SOUTHERN CALIFORNIA EDISON CO4rights of way
- BUREAU OF RECLAMATION2rights of way
- Holder not listed by BLM2rights of way
- MOTOROLA INC1right of way
- SHELL COMMUNICATIONS1right of way
- T E HININGER & CO1right of way
- FARM-AID1right of way
- BLYTHE RADIO INC1right of way
- FRESHPICT FOODS INC OF BLYTHE1right of way
- MASSEY SAND & ROCK CO1right of way
- PUREGRO CO1right of way
- RIVERVIEW FARM & TILLAGE CO1right of way
- CONTINENTAL TELEPHONE CO OF CA1right of way
- FISHER WIRELESS SERVICES1right of way
- PALO VERDE MUTUAL WATER CO1right of way
- USBR (ARIZONA PROJECT)1right of way
- AMERICAN TOWER CORPORATION1right of way
- RIVERSIDE COUNTY (California) - FACILITIES1right of way
- VERIZON CALIFORNIA INC1right of way
- CINGULAR WIRELESS LEASE ADMIN1right of way
The nearest areas
- McCoy WashCalifornia · 7,834 acres · 1 right of way12miles
- McCoy ValleyCalifornia · 30,554 acres · at least 13 active mining claims, 4 rights of way13miles
- Mule MountainsCalifornia · 4,091 acres · nothing placed inside23miles
- Mule McCoy LinkageCalifornia · 60,261 acres · at least 2 active mining claims and 22 more BLM lists as Filed, 8 rights of way23miles
- Upper McCoyCalifornia · 40,628 acres · at least 24 active mining claims, 2 rights of way25miles
More from BLM's Arizona office
Every area BLM's Arizona 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 Big Marias. 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