Montana · Area of Critical Environmental Concern
Sand Arroyo
BLM found a natural system here, and its plan calls for special management. BLM's records place 1 right of way inside the line today, and nine grazing allotments cover part of it. It covers 12,314 acres and was designated April 22, 1996, in the Miles City RMP (2015). In the plan's name, RMP stands for resource management plan. The plan's name carries a later year than that date: BLM's map gives the date it records for the area, and a plan approved later can carry forward an area designated earlier.
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.
- MT STATE HWY COMMISSION1right of way
Grazing allotments
9 grazing allotments cover part of this line. Their permittees aren't named here yet.
- BOBCAT CREEK12,459acres
- FERGUSON11,824acres
- SPRING CREEK7,679acres
- FERGUSON ALLOTMENT7,458acres
- NORTH5,512acres
- BLEVINS ALLOTMENT4,997acres
- REES3,022acres
- POINTER1,896acres
- RORVIK PLACE1,888acres
The nearest areas
- Bug CreekMontana/Dakotas · 3,839 acres · 2 grazing allotments covering part of it12miles
- Ash Creek DivideMontana/Dakotas · 8,283 acres · 6 grazing allotments covering part of it18miles
- Long Medicine WheelMontana/Dakotas · 179 acres · a grazing allotment covering part of it20miles
- Flat CreekMontana/Dakotas · 339 acres · a grazing allotment covering part of it25miles
- Mountain PloverMontana/Dakotas · 24,793 acres · at least 50 active mining claims, 8 grazing allotments covering part of it38miles
More from BLM's Montana/Dakotas office
Every area BLM's Montana/Dakotas 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 Sand Arroyo. 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