GMU 100 GMU 100 — Washington/Morgan Co.
Wide-open shortgrass and dryland-farm country built for pronghorn and plains mule deer
Northeastern Colorado plains — Washington & Morgan Counties · Last reviewed 2026-07-12
Area
1,061
sq mi
Public land
6%
approx.
Elevation
4,200–4,900
feet
Motorized
extensive
access
Overview
GMU 100 is a large (roughly 1,060-square-mile) block of northeastern Colorado plains in Washington and Morgan Counties, bounded by US 34 on the north, County Road 61 on the east, US 36 on the south, and County Road 71 on the west. This is agricultural, ranch-dominated country — 90-plus percent private — where pronghorn is the marquee species and plains mule deer the strong second, while elk are essentially incidental (a single animal taken recently). Success here is far more about securing private-land access than about finding animals.
Terrain
Flat to gently rolling High Plains — some of the easiest terrain to walk in the state. Shortgrass prairie mixes with dryland and irrigated cropland, sandsage draws, sandy hills, and scattered creek and shelterbelt bottoms that break up the open expanse.
Cover: Shortgrass prairie (roughly 10-15% of the unit) interspersed with dry and irrigated cropland (wheat, corn, milo), sandsage and mid-grass draws, CRP grassland, and cottonwood/shelterbelt strips along the drainages.
Landmarks: US 34 corridor (north) · US 36 corridor (south) · County Road 71 (west) · County Road 61 (east) · Akron area · sandsage draws and CRP tracts
Access
Overwhelmingly private — roughly 94% — with only a thin sliver of genuinely huntable public ground. The 'state' land shown on maps is Colorado State Trust land, which is NOT open to hunting unless the specific parcel is enrolled in CPW's Public Access Program (walk-in access), so do not assume it is huntable. Success hinges on landowner permission, a leased ranch, an outfitter, or CPW walk-in tracts. County roads make the country easy to reach and glass from, but the land beyond the fence is almost all private.
Managers: private ranch and farm, Colorado State Trust land (generally closed to hunting), scattered public
Access points: US 34 · US 36 · County Road 71 · County Road 61 · county road grid throughout
Species notes
Pronghorn
common qualityThe headliner. Pronghorn thrive in this open shortgrass-and-cropland country and recent hunters filled roughly 70% of tags (about 50 animals taken). Landowners are generally more willing to grant pronghorn access than deer access, making this the unit's best opportunity.
- →Glass the open shortgrass flats and crop edges from county roads at first and last light, then plan a stalk on private ground you have permission for.
- →Use the subtle swales, draws, and terrain rolls of the plains to close the final distance on a bedded buck.
- →Line up private-land access or a CRP/walk-in tract before the season — access is the whole game out here.
Mule Deer
common qualityA solid plains mule deer opportunity on the sandsage draws, CRP, and cropland edges, with recent success around 55% (roughly 105 deer taken). Limited-draw like all Colorado deer. Access-limited but productive where you can hunt.
- →Focus on sandsage and mid-grass draws, CRP fields, and the cover strips along drainages where plains muleys hold during the day.
- →Hunt the edges between cropland feed and brushy bedding cover early and late.
- →Secure permission on specific ranches ahead of time; deer access is harder to get than pronghorn access here.
Whitetail Deer
limited opportunityWhitetails occur in smaller numbers along the creek bottoms, cottonwood corridors, and shelterbelts, mixing with mule deer. A secondary, access-dependent opportunity in the wooded riparian pockets.
- →Key on cottonwood bottoms, tree-lined drainages, and shelterbelts rather than the open prairie.
- →Hunt travel routes between riparian bedding cover and adjacent crop fields at dawn and dusk.
- →Verify which deer species your tag covers and confirm private-land permission on the river/creek bottoms.
Rocky Mountain Elk
transient lowElk are incidental on these plains — just one animal taken recently at low success. Wandering, transient animals rather than a resident herd; not a species to plan a trip around.
- →Treat any elk as an opportunistic encounter while hunting pronghorn or deer, not a target.
- →Watch large CRP blocks and cropland where a stray elk might hold.
- →Focus your effort and access work on pronghorn and mule deer instead.
Pro tips
- →Access is everything — 94% of GMU 100 is private, so secure permission, a lease, an outfitter, or CPW walk-in tracts before the hunt.
- →Do not count State Trust land as huntable unless the parcel is enrolled in CPW's Public Access Program.
- →Pronghorn is the highest-odds, easiest-to-access species here — landowners grant antelope permission more readily than deer.
- →Glass from the county-road grid to locate animals, then hunt only ground you have permission for.
- →After rain, dirt county roads turn to gumbo — plan routes accordingly.
Watch out for
- !Roughly 94% private land — trespass risk is high; get permission in writing and know boundaries.
- !Colorado State Trust land is closed to hunting unless enrolled in CPW's Public Access Program.
- !Very little genuinely open public ground — do not assume map 'state' parcels are huntable.
- !Dirt county roads become impassable gumbo when wet.
- !Confirm which deer species your tag covers where mule deer and whitetail overlap.
Logistics
Easy-access plains country served by a dense county-road grid and paved US 34/36. Akron sits near the center of the unit; Fort Morgan and Brush to the west and Yuma to the east offer fuel, groceries, motels, and repair. Standard vehicles handle most dry county roads, though dirt turns to gumbo after rain. The real logistics challenge is not terrain but access — line up permission, a lease, or CPW walk-in tracts well before opening day.
Nearest towns: Akron, CO, Fort Morgan, CO, Brush, CO, Yuma, CO
Seasons & regulations
This page carries no season dates or regulations. Get current rules from the official Colorado sources:
Research sources: CPW Hunting Pronghorn · CPW Game Management Units (GIS) · HuntScore — Colorado GMU 100 (secondary cross-check)
FAQ
- How big is GMU 100 in Colorado?
- GMU 100 (GMU 100 — Washington/Morgan Co.) covers about 1,061 square miles, ranging from roughly 4,200 to 4,900 feet in elevation. Area is computed from the unit boundary polygon.
- How much public land is in GMU 100?
- Approximately 6% of the unit is public land. Primary managers: private ranch and farm, Colorado State Trust land (generally closed to hunting), scattered public. Always verify ownership boundaries on the ground.
- What species does the catalog list for GMU 100?
- Pronghorn, Mule Deer, Whitetail Deer, Rocky Mountain Elk. For seasons, tags, and regulations, use the official Colorado agency resources linked on this page — this page carries no regulatory information.
Put GMU 100 on your map.
Boundary lines, public/private ownership, topo, and offline maps for this unit — in Baseline Maps, free for 14 days.