Unit 66A 66A (Diamond Creek)
Timbered Caribou Range country between Palisades Reservoir and Grays Lake — a limited-tag zone built for mature bull elk.
Southeast Idaho — Diamond Creek & Caribou Range (Bonneville/Caribou Counties) · Last reviewed 2026-07-12
Area
267
sq mi
Public land
68%
approx.
Elevation
6,000–9,803
feet
Motorized
moderate
access
Overview
Unit 66A covers the forested Caribou Range and Diamond Creek country between Palisades Reservoir and Grays Lake National Wildlife Refuge in Bonneville and Caribou Counties. It is mostly public — about two-thirds Caribou-Targhee National Forest — running from McCoy Creek and Herman down to Highway 34 near the Wyoming line. Lower slopes are a mosaic of bigtooth maple, chokecherry, serviceberry and sagebrush meadows climbing into conifer, while Grays Lake's cattail marsh anchors the southwest. Elk are the prize in this limited-entry Diamond Creek Zone, hunted by lottery rifle tags and first-come archery permits that protect mature bulls; mule deer are present in fair numbers, black bears use the brush and timber, and Shiras moose are a high-success once-in-a-lifetime draw.
Terrain
Rolling brush-and-meadow foothills near 6,000 ft rising into the steep, timbered Caribou Range topped by Caribou Mountain (9,803 ft), with the Grays Lake marsh basin to the southwest.
Cover: Lower elevations of bigtooth maple, chokecherry, serviceberry and scattered juniper mixed with sagebrush and grassy meadows; conifer forest on the higher slopes; cattails, bulrush and willow in the Grays Lake wetlands.
Landmarks: Caribou Mountain (9,803 ft) · Diamond Creek · Grays Lake National Wildlife Refuge · McCoy Creek · Caribou Range · Palisades Reservoir (west edge)
Access
About 66% Caribou-Targhee National Forest across both the Caribou and Targhee divisions forms the accessible core, with private ground on the lower benches and valley edges and the Grays Lake NWR in the southwest. No designated wilderness, so motorized travel is permitted on open Forest roads. No Access Yes! properties.
Managers: USFS Caribou-Targhee NF (Caribou & Targhee), Private, State of Idaho, USFWS Grays Lake NWR
Access points: McCoy Creek Rd (FS Rd 087) · Bone Rd · State Highway 34 · Diamond Creek drainage · Caribou-Targhee NF boundary trailheads
Species notes
Rocky Mountain Elk
abundant trophyThe headline species — the Diamond Creek Zone is a limited-entry unit with good elk numbers managed for mature bulls, drawing rifle tags by lottery and offering first-come archery permits. Strong harvest and quality bull potential for those who get in.
- →Glass the maple-and-meadow benches and Diamond Creek basins at dawn and dusk
- →Bugle the September timber and aspen ridges for mature bulls
- →Hunt travel corridors between feed on the brushy foothills and dark-timber bedding
- →Be ready for physically demanding, steep country
Mule Deer
common qualityFair numbers of mule deer inhabit the brushy foothills and maple draws; a general-season opportunity with some mature bucks in the mix.
- →Glass the bigtooth maple, serviceberry and sagebrush benches morning and evening
- →Hunt the brushy draws and pockets that hold bucks
- →Push higher into conifer edges as pressure builds
- →Time later hunts for migrating deer
Black Bear
common opportunityBlack bears thrive on the maple, chokecherry and serviceberry brush and timbered slopes; a strong spring green-up and fall berry opportunity.
- →Spring: glass green south-facing slopes and old cuts
- →Fall: hunt chokecherry, serviceberry and maple brush fields
- →Watch for cinnamon color-phase bears
- →Still-hunt timbered draws on quiet mornings
Moose
limited trophyShiras moose are a once-in-a-lifetime controlled tag with very high success; bulls hold in the willow bottoms, creek drainages and Grays Lake wetland margins.
- →If you draw, scout willow flats and creek bottoms early
- →Glass the Grays Lake wetland edges and riparian corridors at dawn and dusk
- →Hunt slow through thick brush
- →Expect a long point wait to draw
Pro tips
- →This is a coveted limited-entry elk unit — securing a Diamond Creek tag is the whole game; know the lottery-rifle vs. first-come-archery structure
- →It's steep, physical country — come in shape and plan for deep pack-outs
- →Glass the brushy maple-and-meadow benches hard; elk and deer feed the openings and bed the timber
- →Fall frost thins the maple brush and improves visibility for glassing
- →Apply early for the once-in-a-lifetime moose tag — success is very high once drawn
Watch out for
- !Remote, physically demanding terrain with long pack-outs — prepare for backcountry conditions
- !High archery-season pressure despite limited tags
- !Private inholdings on the lower benches and valley edges — verify boundaries
- !Grays Lake NWR carries its own access and use rules
- !Upper Caribou Range roads snow shut early
Logistics
Highway 34 and the McCoy Creek/Bone roads are the main arteries; Soda Springs to the south and Idaho Falls to the northwest are the supply, fuel, lodging and processing hubs. Forest access branches off McCoy Creek Rd and the Diamond Creek drainage — remote country where you should carry recovery gear and full fuel.
Nearest towns: Soda Springs, Freedom, Wayan, Idaho Falls, Swan Valley
Seasons & regulations
This page carries no season dates or regulations. Get current rules from the official Idaho sources:
Research sources: IDFG Hunt Planner — Unit 66A · IDFG Diamond Creek Zone — Hunt Planner · GOHUNT — Idaho Unit 66A Profile
FAQ
- How big is Unit 66A in Idaho?
- Unit 66A (66A (Diamond Creek)) covers about 267 square miles, ranging from roughly 6,000 to 9,803 feet in elevation. Area is computed from the unit boundary polygon.
- How much public land is in Unit 66A?
- Approximately 68% of the unit is public land. Primary managers: USFS Caribou-Targhee NF (Caribou & Targhee), Private, State of Idaho, USFWS Grays Lake NWR. Always verify ownership boundaries on the ground.
- What species does the catalog list for Unit 66A?
- Rocky Mountain Elk, Mule Deer, Black Bear, Moose. For seasons, tags, and regulations, use the official Idaho agency resources linked on this page — this page carries no regulatory information.
Put Unit 66A on your map.
Boundary lines, public/private ownership, topo, and offline maps for this unit — in Baseline Maps, free for 14 days.