GMU 146 GMU 146 — Bent/Prowers Co.
Arkansas River farm-and-prairie country — pronghorn and deer on a nearly all-private unit
Southeast Colorado plains — Bent & Prowers County shortgrass prairie · Last reviewed 2026-07-12
Area
934
sq mi
Public land
4%
approx.
Elevation
3,622–4,600
feet
Motorized
extensive
access
Overview
GMU 146 is a large (roughly 934-square-mile) plains unit in Bent and Prowers Counties, bounded by the Arkansas River to the north, US 287 to the east, the Baca County line to the south, and County Highway 101 to the west. This is flat-to-gently-rolling shortgrass prairie broken by sand sage, dryland and irrigated farm ground, and cottonwood river bottoms, with a little canyon-mesa country in the south. It is overwhelmingly private — public access is minimal — so a hunt here almost always means securing ranch permission or a leased/access arrangement. Pronghorn and deer are the real quarry; elk are only incidental.
Terrain
Flat to gently rolling high plains cut by the Arkansas River corridor, with scattered sandy sage draws and a bit of canyon-mesa relief toward the south. Low, open, and wind-swept — glassing country where animals are visible at long range but hard to approach.
Cover: Shortgrass prairie with sand sagebrush, dryland wheat and irrigated cropland, yucca, and cottonwood-lined river and creek bottoms.
Landmarks: Arkansas River · John Martin Reservoir (state park — no hunting) · US Highway 287 corridor · sand sage prairie south of the river
Access
About 96% of the unit is private farm and ranch ground — public hunting land is scarce and holds very few animals. Part of the unit falls inside John Martin Reservoir State Park, where hunting is NOT permitted. Colorado State Trust parcels are generally closed to hunting unless enrolled in CPW's Public Access Program. Realistically this is a knock-on-doors, ask-permission, or leased/access unit; do not plan a public-land walk-in hunt here.
Managers: private ranch and farm (dominant), CPW John Martin Reservoir State Park (no hunting), Colorado State Trust (generally closed to hunting)
Access points: US Highway 287 · US Highway 50 / Arkansas River corridor · county roads through the farm country · CPW Public Access Program (PAP) enrolled lands, where available
Species notes
Pronghorn
common opportunityThe unit's marquee big-game animal, scattered across the sage and prairie — but with very few animals on public land, this is a private-access hunt. Recent success ran better than half of tags filled, reflecting good herds on the private ground for those who can hunt it.
- →Line up ranch permission or a CPW Public Access Program parcel before you buy a plan — public antelope hunting here is poor.
- →Glass long across the open sage and prairie from high two-track vantage points, then use terrain and fence lines to close.
- →Focus on sand-sage flats and the edges of dryland ag where bucks hold; hunt water sources in warm early seasons.
Mule Deer
common opportunityMule deer use the sage draws, breaks, and canyon-mesa country away from the river. Public access is fair at best; the better deer are on private ground. Recent buck success ran around a third of tags.
- →Work the sandy sage draws, yucca flats, and any canyon-mesa relief in the south rather than the open farm flats.
- →Glass at first and last light where prairie meets cover; deer bed in the sage and draws during the day.
- →Permission on a ranch with sage-draw structure is the difference-maker.
Whitetail Deer
limited opportunityWhitetail hold in the cottonwood bottoms and brush along the Arkansas River and its tributaries — a classic eastern-plains river-corridor whitetail, but almost entirely on private farm ground.
- →Hunt the cottonwood river bottoms, brushy draws, and cropland edges along the Arkansas where whitetail concentrate.
- →Set up on travel routes between bedding cover in the timber and adjacent ag fields at dawn and dusk.
- →River-bottom access is nearly all private — secure permission on a bottom-ground parcel.
Rocky Mountain Elk
transient lowElk are incidental on this plains unit — a small, scattered presence with very low harvest. Not a species to plan a trip around here.
- →Treat any elk as an opportunistic add-on to a pronghorn or deer hunt on private ground.
- →Watch river-bottom ag and sage country where the few resident elk drift.
- →Do not build a plan around elk in GMU 146.
Pro tips
- →This is ~96% private — arrange ranch permission or a CPW Public Access Program parcel long before season.
- →John Martin Reservoir State Park lies within the unit and is closed to hunting — know that boundary.
- →The Arkansas River cottonwood bottoms are your whitetail play; the sage draws and southern mesas are your mule deer play.
- →State Trust parcels are generally closed to hunting — don't count them as public.
- →Glass big and be willing to cover ground by vehicle on the county-road grid, then stalk on foot.
Watch out for
- !Overwhelmingly private land — public parcels are few and hold very few animals.
- !No hunting inside John Martin Reservoir State Park.
- !State Trust parcels are generally closed unless in CPW's Public Access Program.
- !Open, windy prairie — long shots and hard stalks; know your effective range.
- !Respect ag operations and fences; a trespass here ends access for everyone.
Logistics
Lamar (on US 50/287) and Las Animas are the practical bases for fuel, groceries, motels, and diesel. Services are thin inside the unit itself. This is drive-and-glass country with an extensive county-road grid; a standard vehicle works, but expect wind, dust, and greasy roads after rain. Above all, do the access legwork first — a hunt here lives or dies on permission.
Nearest towns: Lamar, CO, Las Animas, CO, Springfield, CO, Granada, CO
Seasons & regulations
This page carries no season dates or regulations. Get current rules from the official Colorado sources:
Research sources: CPW GMU 146 boundary and big-game statistics · HuntScore — GMU 146 (Bent/Prowers) land ownership and hunt summary
FAQ
- How big is GMU 146 in Colorado?
- GMU 146 (GMU 146 — Bent/Prowers Co.) covers about 934 square miles, ranging from roughly 3,622 to 4,600 feet in elevation. Area is computed from the unit boundary polygon.
- How much public land is in GMU 146?
- Approximately 4% of the unit is public land. Primary managers: private ranch and farm (dominant), CPW John Martin Reservoir State Park (no hunting), Colorado State Trust (generally closed to hunting). Always verify ownership boundaries on the ground.
- What species does the catalog list for GMU 146?
- 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 146 on your map.
Boundary lines, public/private ownership, topo, and offline maps for this unit — in Baseline Maps, free for 14 days.