Idaho · Area of Critical Environmental Concern
Swan Island RNA
BLM found a natural system here, and its plan calls for special management. BLM's records place no claim, lease or right of way inside the line today, and a grazing allotment covers part of it. It covers 38 acres and was designated November 29, 1985, in the Medicine Lodge RMP 1985. 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
Ground: USGS The National Map, topographic tiles. Boundaries: BLM's own, read Oct 20, 2026. The grazing allotment below isn't marked.Grazing allotments
A grazing allotment covers part of this line. Its permittee isn't named here yet.
- Allotment USFS-GRZ-10958.01049519,972acres
The nearest areas
- Pine Creek Island RNAIdaho · 54 acres · a grazing allotment covering part of it8miles
- Game Creek RNAIdaho · 360 acres · a grazing allotment covering part of it18miles
- Snake RiverIdaho · 144,078 acres · at least 1 active mining claim and 4 more BLM lists as Filed, 89 rights of way, 61 grazing allotments covering part of it25miles
- Reid Canal Island RNAIdaho · 29 acres · nothing placed inside30miles
- Travertine Park RNAIdaho · 23 acres · 2 grazing allotments covering part of it37miles
Next to it
Snake River Area of Critical Environmental Concern touches the line.
More from BLM's Idaho office
Every area BLM's Idaho 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 Swan Island RNA. 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