GMU 163 Marengo
Private Palouse-and-breaks deer ground north of Dayton — an improving whitetail/mule deer unit where elk are a nuisance, not a season.
Region 1 — Blue Mountains foothills / Palouse (Eastern WA) · Last reviewed 2026-07-12
Area
151
sq mi
Public land
5%
approx.
Elevation
1,600–4,500
feet
Motorized
moderate
access
Overview
GMU 163 "Marengo" wraps the foothill and Palouse-prairie country north and east of Dayton in Columbia and Garfield counties, bounded by U.S. Highway 12, the Patit and Tucannon drainages, and Tatman Mountain. WDFW describes it as predominantly private land — a farm-forest mosaic of dryland wheat, CRP grass, rangeland, and brushy draws that flatten out of the Blue Mountains rather than climbing into their timbered core. It is a deer unit first: white-tailed and mule deer share the draws and ag edges, and Marengo has shown a recent increase in hunter success even as it stays a moderate-density unit. Elk are essentially incidental — WDFW does not manage 163 for elk and it only occasionally holds enough to hunt, with any opportunity driven by agricultural-damage management rather than a huntable resident herd.
Terrain
Palouse-prairie and Blue Mountains foothill country dissected by steep draws and canyons. Broad dryland-wheat and CRP benches and rolling grassland fall away into brushy creek breaks along the Patit and Tucannon drainages, ranging from roughly 1,600 ft in the valleys up to the ~4,000-4,500 ft foothill shoulders around Tatman Mountain. This is the transition zone below the forested high plateau, not the timbered mountains themselves.
Cover: Dryland wheat, CRP and rangeland grasses, and brushy grass draws dominate, with riparian brush, hawthorn, and berry shrubs along the creek bottoms and scattered ponderosa pine and Douglas fir on the higher foothill fringes. North-facing draws and creek corridors hold the thickest cover that concentrates deer.
Landmarks: Town of Dayton (southwest corner, Hwy 12 junction) · Patit Creek / Patit Road (south boundary drainage) · Tucannon River / Tucannon Road (east boundary) · Tatman Mountain (northern foothill high ground) · U.S. Highway 12 corridor (southwest boundary) · Marengo locale (namesake, on the Tucannon)
Access
GMU 163 is predominantly private farm and ranch land, so like most of the District 3 Palouse/foothill units, access is the main constraint rather than terrain. There is little to no significant public block inside the unit — opportunity depends on landowner permission and on parcels enrolled in WDFW's private-lands hunting-access programs (Feel Free to Hunt, Hunt by Written Permission, Register to Hunt). Identify enrolled tracts on the Region 1 Private Lands access map and arrange written-permission access well before the season. Road access across the ag country is generally good, but most roads front private ground.
Managers: Private agricultural and ranch landowners (the large majority), Private landowners enrolled in WDFW hunting-access programs (Feel Free to Hunt / Hunt by Written Permission / Register to Hunt)
Access points: U.S. Highway 12 / Patit Road corridor out of Dayton · Tucannon Road along the eastern breaks · Tatman Mountain Road (north) · WDFW private-lands access-program parcels (Region 1 Private Lands map)
Species notes
Whitetail Deer
common opportunityWhitetails are well established in the brushy creek bottoms, CRP, and farm-edge cover of the Patit and Tucannon breaks and are a mainstay of the unit's deer harvest. WDFW notes GMU 163 has seen a recent increase in hunter success. The District 3 whitetail segment was set back by the 2021 hemorrhagic-disease (EHD/bluetongue) outbreak at lower elevations but has been recovering with successive mild winters.
- →Hunt the brushy draws, CRP edges, and riparian corridors where whitetails bed by day and feed at field margins at dawn and dusk
- →Glass field and cover edges from vantage points; still-hunt thick creek bottoms during the rut and try rattling/calling
- →Almost all the ground is private — secure landowner or access-program permission before the season
- →Numbers are improving four years post-EHD; expect better whitetail hunting but watch for reduced antlerless allowances in recovery years
Mule Deer
common opportunityMule deer share the foothills and breaks with whitetails, favoring the more open grassland benches, CRP, and timber-edge fringes higher in the unit. Marengo is a moderate-density deer unit (harvest around 0.66 deer/mi2) that has been trending up in hunter success. Managed for opportunity, not trophy quality.
- →Glass open CRP and grass benches and draw heads at first and last light, then still-hunt shaded pockets mid-day
- →Muleys hold on the more open higher country; work the timber-edge fringes toward the foothills
- →Access is everything on this private ground — line up permission or access-program parcels before scouting
- →Expect younger bucks reaching legal point counts; this is a general-opportunity unit
Rocky Mountain Elk
transient lowGMU 163 is not managed for elk and only occasionally supports enough elk to hunt. As part of the single Blue Mountains herd it sees transient elk moving out of the higher units, and any opportunity is tied to agricultural-damage management on private land rather than a resident, huntable population. Do not plan a trip around elk here.
- →Treat elk as opportunistic only — the unit is managed to limit elk, not grow them
- →Any elk are on private ag ground; access and current permit/damage-hunt structure govern whether you can hunt them at all
- →Focus your energy on deer; check the pamphlet for any damage or special-permit elk hunts before counting on elk
Black Bear
limited opportunityBlack bears occur in the Blue Mountains but at lower density in a Palouse/foothill unit like Marengo than in the forested GMUs to the south (Blue Creek/154, Dayton/162 lead the district). Bears here are taken opportunistically along brushy creek corridors and berry draws. Note the Aug 1 opener and two-bear statewide limit.
- →Focus the brushier creek bottoms and berry-rich draws early and late in the day
- →Glass open slopes bisected by shrubby draws from a vantage with good visibility
- →This is a lower-density bear unit — expect incidental encounters rather than a dedicated bear destination
Cougar
limited opportunityCougars follow the deer through the foothill breaks and draws. As statewide, the season runs under a regional harvest cap and closes once the cap is met, and hound use is prohibited (I-655), so harvest is almost entirely incidental to deer hunting.
- →Carry a tag while deer hunting — most cougars are taken by hunters who cut fresh tracks or catch a cat moving
- →Hunt the brushy draws and breaks that hold deer; cats follow the prey
- →Watch the regional quota status — the season can close on short notice; fresh snow improves tracking odds
Pro tips
- →Marengo is a deer unit, not an elk unit — WDFW does not manage 163 for elk and it only occasionally holds huntable elk. Come for whitetails and mule deer.
- →Success here has been trending up recently — a good pick if you can line up private access on the Patit/Tucannon breaks.
- →Access is the whole game: pull the Region 1 Private Lands access map and secure Feel Free to Hunt / Hunt by Written Permission parcels or landowner permission before the season.
- →Split your effort — whitetails in the brushy creek bottoms and CRP edges, mule deer on the open grass/timber-edge benches.
- →Mandatory CWD testing applies to deer/elk taken in Region 1 (100-series GMUs), and whole carcasses can't be moved out of the 100-series — debone or follow the allowed-parts rules.
Watch out for
- !The unit is predominantly private — don't assume roadside ground is open; arrange access-program or landowner permission ahead of time.
- !There is little significant public land inside 163 — no big federal block to fall back on.
- !Don't plan around elk — the unit isn't managed for them and rarely holds enough to hunt.
- !Hemorrhagic disease (EHD/bluetongue) periodically knocks back low-elevation deer (notably 2021), reducing numbers and antlerless opportunity in recovery years.
- !Chronic wasting disease is confirmed in WDFW's Eastern Region (Spokane area) — mandatory CWD testing and 100-series carcass-transport restrictions apply.
- !The cougar season runs under a regional harvest cap and can close mid-season once the cap is met.
- !Hot, dry late summers raise wildfire risk that can affect foothill back-road access.
Logistics
Dayton (southwest corner) offers gas, groceries, lodging, and restaurants; Waitsburg and Pomeroy add local services and Walla Walla to the southwest is the full-service regional hub with the nearest larger airport. Because the unit is predominantly private, there is little public camping inside it — most hunters day-hunt from Dayton or camp on the Umatilla National Forest to the south. Road access across the ag country is generally good, but sort out private access-program parcels or landowner permission before you go. WDFW's Region 1 office (Spokane Valley, 509-892-1001) and District 3 biologists can help with access questions.
Nearest towns: Dayton, WA, Waitsburg, WA, Pomeroy, WA, Walla Walla, WA
Seasons & regulations
This page carries no season dates or regulations. Get current rules from the official Washington sources:
Research sources: WDFW — Game Management Units (GMUs) · WDFW — 2025 District 3 Hunting Prospects (Walla Walla, Columbia, Garfield, Asotin counties) · WDFW — GMU 163 Marengo boundary description · WDFW — Blue Mountains Elk Herd Management Plan
FAQ
- How big is GMU 163 in Washington?
- GMU 163 (Marengo) covers about 151 square miles, ranging from roughly 1,600 to 4,500 feet in elevation. Area is computed from the unit boundary polygon.
- How much public land is in GMU 163?
- Approximately 5% of the unit is public land. Primary managers: Private agricultural and ranch landowners (the large majority), Private landowners enrolled in WDFW hunting-access programs (Feel Free to Hunt / Hunt by Written Permission / Register to Hunt). Always verify ownership boundaries on the ground.
- What species does the catalog list for GMU 163?
- Whitetail Deer, Mule Deer, Rocky Mountain Elk, Black Bear, Cougar. For seasons, tags, and regulations, use the official Washington agency resources linked on this page — this page carries no regulatory information.
Put GMU 163 on your map.
Boundary lines, public/private ownership, topo, and offline maps for this unit — in Baseline Maps, free for 14 days.