Unit 591, Colorado

Rolling shortgrass prairie dominates the eastern portion of the unit; rimrock cliffs, broad mesas, plateaus, creeks, canyons, and draws characterize the middle and western sections; flat prairies extend across the south. Elevation ranges from approximately 5,500 to 6,700 feet. Some interior roads are surfaced with sharp-edged shale and require four-wheel-drive in wet conditions.

GMU 591 is entirely within Fort Carson Military Reservation (~94,000 acres) and is managed under the Army's iSportsman recreation system. All hunters must: (1) create a one-time iSportsman account at fortcarson.isportsman.net; (2) read FC Regulation 200-6 and sign a Hold Harmless Agreement; (3) complete an annual downrange safety briefing and UXO safety briefing; (4) purchase an annual Fort Carson recreational permit (valid April 1 through the following March 31) only after completing the safety briefs; (5) register all firearms with the Provost Marshal's Office using FC Form 66-E (allow 6+ weeks); (6) obtain a daily downrange pass for specific areas and dates via iSportsman online check-in — pass must be printed or handwritten and displayed on vehicle dashboard. Non-DoD ID holders must check in at Gate 1 (Visitor Control Center, south Colorado Springs, off I-25) with hunting credentials and undergo a criminal background check before receiving an installation pass; a Real ID or two forms of ID are required. Hunters may enter and exit through any manned gate: Gates 1, 3, and 20 are always open; Gates 4, 5, 6, and 19 are open when conditions allow. Open hunting blocks are published weekly (most Thursdays or Fridays) on the iSportsman areas page and reflect daily military training schedules — access can be closed with no advance notice. Weapon restrictions by block: Training Areas 4, 5, and 51 (Blocks 1, 2, 17) are archery-only; Training Areas 8, 9, 11, 12, 13, 14, 16, 20, 24, 25, 28, and 29 (Blocks 3, 4, 6, 8, 10) are low-velocity only (archery, muzzleloader, or shotgun); remaining blocks allow any legal weapon unless restricted by Range Control. Fluorescent orange is mandatory during rifle and muzzleloader seasons even in archery-only or low-velocity areas. Waterfowl hunting is prohibited at all Fort Carson reservoirs. No National Forest, BLM, or state-owned land lies within the unit. There is no private-land checkerboard; the entire unit is federally owned Army land.

Dominant cover types include shortgrass prairie (blue grama, buffalo grass), pinyon-juniper woodland, oakbrush (Gambel oak), sagebrush, bitterbrush, yucca, ponderosa pine, cottonwood and willow riparian corridors along creek drainages, and scattered aspen. No spruce-fir or alpine tundra present at these elevations.

Elk are the primary draw and herds have been growing, concentrating in the canyons and draws on the western and southern portions of the installation. Elk may move seasonally between Fort Carson and adjacent GMU 59 to the north and west as military training activities fluctuate. Mule deer inhabit the west and south sides of the unit. White-tailed deer are present along riparian corridors. Pronghorn occupy the northwestern grasslands, though populations have been described as declining in recent seasons. Black bear and mountain lion are present on post. Wild turkey occurs on post. Bighorn sheep are not documented within GMU 591 proper — bighorn hunts occur at the adjacent Piñon Canyon Maneuver Site, a separate unit. No moose documented. Bull elk are subject to a mandatory antler restriction in all seasons: 4 points or more on one antler, OR a brow tine of at least 5 inches.

1. GMU 591 is entirely Fort Carson Military Reservation (~94,000 acres per DVIDS) — all access is through the Army iSportsman permit system. The 99% public_land_pct reflects federal ownership but access is controlled military land, not open public land. 2. Harvest stats (elk 2nd rifle ~16%, mule deer rifle ~55%, pronghorn muzzleloader ~66%, elk harvest 11, deer harvest 52, pronghorn harvest 4) are sourced from the 2024-2025 Fort Carson harvest summary PDF and reflect only hunters who hunted on Fort Carson. The PDF was not directly readable by fetch tool; these figures carry forward from the draft and should be verified against the raw PDF. 3. The 138,000-acre figure in the original draft is not supported by authoritative sources — DVIDS and iSportsman cite ~94,000 acres for Fort Carson proper (PCMS is a separate ~224,000-acre installation). 4. Archery-only areas corrected: iSportsman areas page identifies Blocks 1 (TA4), 2 (TA5), and 17 (TA51) as archery-only — not 'TAs 2-6' as stated in draft. 5. Season dates are 2026 statewide CPW structure per Raghorn Outfitters; Fort Carson may run extended windows — verify in current CPW big game brochure and iSportsman portal. 6. Swift fox hunting is prohibited on Fort Carson. Prairie dog hunting is currently closed. Waterfowl hunting is prohibited at all Fort Carson reservoirs. 7. Nonresident archery elk OTC eligibility for GMU 591 (east of I-25) should be confirmed in the current CPW big game brochure. 8. Draw odds data not sourced; consult CPW draw recap reports.