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Wyoming · Area of Critical Environmental Concern

South Pass Historical Landscape ACEC

BLM found a historic value and a natural hazard here, and its plan calls for special management. BLM's records place at least 485 active mining claims (and 942 more BLM lists as Filed or Under Review) and 50 rights of way inside the line today, and 20 grazing allotments cover part of it. It covers 158,545 acres and was designated June 26, 2014, in the Lander Resource Management Plan.

Acres158,545
DesignatedJun 26, 2014Lander Resource Management Plan
BLM founda historic value and a natural hazardand found it important
Inside, at least555claims, rights of way and allotments, and 942 more claims BLM lists as Filed or Under Review

BLM's map carries a second area of nearly the same name: the South Pass Historic Landscape ACEC, 53,773 acres, designated December 22, 2024, in the Rock Springs Resource Management Plan. They're two areas from two plans, and both are counted. Their lines meet along about 19.5 km and overlap on 10.4 acres. BLM's list of past areas also carries a row for this one, with the same acres and date. BLM's map of designated areas carries it too, so we count it.

The line

South Pass Historical Landscape ACEC
Mining claim, 380Claimant withheld by BLM, 105Filed, 892Under Review, 14Filed, claimant withheld, 35Under Review, claimant withheld, 1Right of way, 50
Ground: USGS The National Map, topographic tiles. Boundaries: BLM's own, read Oct 20, 2026. 141 marks are where BLM's own maps draw them; 1,336 claims are placed at the middle of the section their land description names, not at the stakes on the ground. Hover or tap one for its holder. The 20 grazing allotments below aren't marked.

Who holds the claims

At least 1,427 claims sit inside this line: 485 active and 942 filed and pending, 1,286 with a holder BLM names and 141 with a claimant BLM withholds under the Privacy Act. BLM lists 927 as Filed, 485 as Active and 15 as Under Review.

  • RELEVANT GOLD HOLDINGS US INC1,055claims
  • Names withheld by BLM (private individuals)141claims
  • GOLDEN BUFFALO MINING87claims
  • Relevant Gold Holdings US Inc43claims
  • LOST CREEK CORPORATION40claims

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

50 rights of way sit inside the line. BLM files 39 under non-energy facilities and 11 under other energy facilities.

  • PACIFICORP10rights of way
  • Holder not listed by BLM8rights of way
  • FREMONT COUNTY (Wyoming)7rights of way
  • WYOMING DEPARTMENT OF TRANSPORTATION4rights of way
  • QWEST CORP3rights of way

Grazing allotments

20 grazing allotments cover part of this line. Their permittees aren't named here yet.

  • ANTELOPE HILLS197,226acres
  • Continental Peak88,417acres
  • ATLANTIC CITY COMMON49,794acres
  • SILVER CREEK COMMON38,255acres
  • Pine Creek18,829acres

The nearest areas

Next to it

South Pass Historic Landscape Area of Critical Environmental Concern touches the line.

More from BLM's Wyoming office

Every area BLM's Wyoming office holds

The proposed rule

A proposed rule, RIN 1004-AF53, would change how BLM drafts every land use plan, and how it designates ACECs like South Pass Historical Landscape 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

Watch the ruleWhere the rule stands