Questions people ask about Areas of Critical Environmental Concern

What's an Area of Critical Environmental Concern?

It's public land the Bureau of Land Management has singled out as needing special care, ACEC for short. The name is the government's own, from the Federal Land Policy and Management Act of 1976, which defines it in one sentence: land where special management attention is required to protect a historic, cultural or scenic value, fish and wildlife, or a natural system, or to protect people from a natural hazard. BLM's map showed 1,120 of them on Oct 20, 2026. Start from zero, with the law's own words.

Who designates an ACEC, and how?

BLM does, when it approves a land use plan, or a revision or amendment of one, that includes the area. Its rules ask for two findings first, relevance and importance, and the law adds that special management attention has to be required. Before the plan is final, BLM publishes a notice in the Federal Register listing each proposed ACEC and any limits on use that would come with it, with 60 days for public comment. Approving the plan is the designation.

What do "relevance" and "importance" mean?

They're the two tests in BLM's rule, 43 CFR 1610.7-2. Relevance asks whether a significant value is really there: historic, cultural or scenic, a fish or wildlife resource, a natural system or process, or a natural hazard. Importance asks whether it has substantial significance, which generally means more than local. BLM's map fills in no importance finding for 237 areas, every area in the Idaho and Montana/Dakotas offices among them. BLM's rules ask for the finding before any designation. Where the map leaves it blank, we haven't read the plan to say.

Does designation protect the land, and from what?

Designation doesn't by itself close the land or turn it into a park. The plan that designates an area says what special management it gets, and that can limit what BLM permits inside the line. In the six state offices that fill BLM's "protect" field, it's marked yes for 515 of their 755 areas. BLM defines the field as guarding against irreparable damage to the area's values. One rule applies to every designated ACEC: BLM's mining rules require a plan of operations for mining that disturbs the surface beyond casual use.

Are ACECs only in the West?

On BLM's map, yes. All 1,120 are managed by 11 of BLM's state offices, Alaska and ten in the lower 48, and they cover 25.0 million acres. BLM's own national table lists none for its Eastern States office. California has the most lines, 238, and the most acres.

Is there one near me?

Type your ZIP on the front page and it draws every line within 40 miles of your ZIP's middle, nearest first. A ZIP with none that close gets its three nearest. You can also explore the map, or start from a BLM state office: Alaska, Arizona, California, Colorado, Idaho, Montana/Dakotas, Nevada, New Mexico, Oregon/Washington, Utah and Wyoming. Each office's page lists every area it manages.

Can you mine, drill or graze inside an ACEC?

Designation doesn't by itself close the land, and many lines have claims, leases or grazing inside them. On Oct 20, 2026 our count found at least 11,740 active mining claims and leases inside 237 of the 1,120 lines, 4,646 rights of way, and grazing allotments on part of 789 lines. What a plan permits inside its lines is in the plan. BLM's map doesn't carry it, so neither do we. Read more about what sits inside.

Why are there mining claims inside them?

Because designation doesn't by itself close the land. The plan decides what's limited inside each line. What BLM's mining rules add for every designated ACEC is a step: mining that disturbs the surface beyond casual use needs a plan of operations. Four areas in the California desert hold at least 3,631 of the active claims: Fremont-Kramer, Pinto Mountains, Ivanpah and Picacho. Whether a claim was located before its area was designated is on the area's page once we've read every one of its claims' dates from BLM's register: 35 of the 205 areas with claims so far.

Who holds the most inside the lines, and how do we know?

By our count, RED RIVER CREEK MINING GROUP LLC holds the most: 1,463 claims, most in Fremont-Kramer. BLM's map says where a claim or lease is but not who holds it, so we read the holder from BLM's case records one case at a time, and from BLM's serial index for claims its map doesn't draw. We don't print a private person's name. BLM withholds the holder on 1,832 claims inside the lines, and where its record names a private individual, as it does on 103 more, we show "A private individual, name withheld by this site". The top ten are on the front page.

Why do claim counts say "at least"?

Because some claims can't be placed on the ground, and a claim with no point is inside no line. Claims come from BLM's serial index read whole: 563,300 open claims in the Nevada Division of Minerals' copies, edited Oct 20, 2026 and read by us the same day. BLM's claims map draws 192,391 of them. We placed 312,803 more by the land description BLM records, at its section or quarter, and 58,102 couldn't be placed, most in unsurveyed sections. The other 4 aren't in our records yet. So a count inside a line is still a floor. We checked our placement against the index's own for 5 areas: for Fremont-Kramer, the index's placement puts 2,179 claims inside the line and ours finds 2,171. Read how we placed them.

What's the rule at the White House?

RIN 1004-AF53, "Planning and Designation of Areas of Critical Environmental Concern." It's a proposed rule that would change how BLM drafts every land use plan, and how it designates ACECs. The White House review office got it on July 13, 2026, and finished 87 days later, on October 8, 2026. The government labels it Deregulatory. Its text isn't public until the Federal Register prints it. Read more on the rule page.

When can I comment on it?

Not yet. The proposed rule wasn't in the Federal Register at our last check, Oct 18, 2026, 12:36pm PT, so the comment window isn't open. The comment window opens the day the Federal Register publishes the proposed rule, and the Register sets the deadline that day. We're checking the Federal Register and its public inspection desk every 15 minutes. The Watch sends one email the day it prints.

What are OIRA and "Consistent with Change"?

OIRA is the office inside the White House budget office, the Office of Management and Budget, that reviews significant draft rules before an agency can print them. "Consistent with Change" is reginfo.gov's word for a review OIRA concluded after the rule changed while under review, at OIRA's suggestion or for another reason; the label doesn't say which. OIRA concluded its review of this rule that way on October 8, 2026.

Who met with the White House about it?

While OIRA held the rule, 8 outside groups asked for meetings, which OIRA logs: seven meetings, plus one group OIRA lists as a no-show. The meetings held were asked for by Defenders of Wildlife, Wild Montana, Conservation Lands Foundation, The Pew Charitable Trusts, The Wilderness Society, Sierra Club and National Mining Association. The rule page lists each meeting, everyone OIRA lists in the room and the documents they handed over.

What happened to the 2024 Public Lands Rule?

BLM published it on May 9, 2024, 89 FR 40308, and it rewrote BLM's ACEC rules. BLM proposed rescinding it on September 11, 2025, and a final rule published May 12, 2026, 91 FR 25787, rescinded it, putting the 1983 ACEC rule back, effective June 11, 2026. In it BLM wrote that it may pursue further rulemaking on ACECs in a separate process. Read the full history of the ACEC rules.

What happened to BLM Manual 1613?

BLM's 1988 manual on ACECs, Manual 1613, spelled out how BLM applies the relevance and importance tests. BLM replaced it on August 7, 2024, and rescinded that replacement on May 29, 2026 without issuing another. We found no BLM statement that the 1988 text governs again. The explainer quotes it for how BLM long read the two tests.

Why did 50 New Mexico areas leave BLM's map?

We don't know. BLM's map stopped showing them on Aug 24, 2026. BLM's list of past areas doesn't carry them either, and we found no plan decision removing them. 44 of them were designated in BLM's Farmington plan. BLM is also reviewing the 2023 mineral withdrawal around Chaco Culture National Historical Park, which its Farmington Field Office handles, and its release names no ACEC. Each area keeps its page here, with what the last read held, and none is counted.

Where do the numbers come from, and how fresh are they?

The areas, their acres and BLM's findings are BLM's own map of designated ACECs, read Oct 20, 2026, 8:25am PT. What's inside the lines is our own count, made Oct 20, 2026, 8:30am PT, and who holds each claim or lease is read from BLM's case records, last on Oct 20, 2026, 8:18am PT. The rule's record is read from reginfo.gov, last on Oct 20, 2026, 9:29am PT. We check the Federal Register and its public inspection desk every 15 minutes. Every figure on the site opens a card with its source and the day we read it, and How we know names every source and every gap.

Why doesn't this match BLM's own published count?

BLM's yearly Public Land Statistics counts 1,171 areas on September 30, 2024, covering 21,530,625 acres. It adds research natural areas to the ACECs, it's dated before 50 New Mexico areas left BLM's map (it gives New Mexico 161, and the map has 112), and its acres come from BLM's surface management database, not the lines. This site counts the 1,120 areas on BLM's map on Oct 20, 2026.

Does this site show nominated areas?

No. This site shows designated areas only. Nominations under consideration in open plans aren't on it. Where an open plan says in the Federal Register that it'll re-evaluate designated ACECs, the area's page says so. Two plans do today, listed on the rule page.

Can I download the data?

We don't offer a download of our own. Every area here comes from BLM's own map of designated ACECs, a public map service. The files this site's pages read are public too: BLM's lines as we simplified them for the map (national.json), the counts by state office (states.json) and every quote with its source and the day we copied it (quotes.json).

How do I find out when the rule prints?

Sign up for the Watch with your email and ZIP. It sends one email the day the Federal Register prints the proposed rule, with the comment deadline read from the Register itself, and one when a line near your ZIP changes on BLM's list, leaves it, or gets something new permitted inside it. You confirm with a click in the first email.

Who makes this site?

More Than Just Parks. It's powered by Public Lands Intelligence, our records system on public land. It reads BLM's own map, BLM's case records, reginfo.gov, the Federal Register and the law itself, and How we know names every source.

How do I correct something?

Email ask@morethanjustparks.com with the page's address. Every area page has a "Tell us" link in its foot that fills it in for you. Every correction we make to a fact is listed on How we know, with the date, the page and what changed. There are none yet since the list started October 18, 2026.