What Do Mule Deer Eat in Wyoming, Montana, Colorado & Idaho - Mule Deer Hunting Tips and Tactics

What Do Mule Deer Eat in Wyoming, Montana, Colorado & Idaho - Mule Deer Hunting Tips and Tactics

What Do Mule Deer Eat in Wyoming, Montana, Idaho & Colorado?

Welcome to Backbone Unlimited. My name’s Matt Hartsky.

In this one, we’re digging into something most hunters skip on their way to glassing knobs and gear lists — forage. Not just plants in general, but what mule deer actually eat across the West.

If you’re serious about chasing big bucks in states like Wyoming, Montana, Idaho, or Colorado — whether it’s velvet archery season, mid-October rifle hunts, or snow-covered late seasons — you have to understand what they’re feeding on, where it grows, and when it matters most.

Mule deer aren’t like elk. They’re not grazers. They don’t pile into open meadows to feed in plain sight. They’re selective browsers, adapted to live in harsh, dry, and highly variable terrain. And the more you understand their feeding behavior, nutritional needs, and plant preferences, the faster you’ll stop wasting time in dead country and start zoning in on those pockets where mature bucks actually live, feed, and grow old.

That means fewer empty glassing sessions, more “oh yeah, this is it” moments, and a much higher chance of turning up the kind of buck that thrives under pressure.

In this breakdown, we’ll cover:

  • How mule deer diets shift across the four seasons.

  • Key plants and shrubs they prefer by region and elevation.

  • How nutrition affects antler growth, fawn survival, and buck behavior.

  • And how human factors like grazing, urbanization, and invasive species are changing what mule deer eat — and where you’ll find them.

Let’s get after it.

Seasonal Mule Deer Diet Shifts

Mule deer are survivors. Their diet changes constantly because what’s available — and what their bodies need — changes just as fast. If you’re trying to figure out why deer disappeared from a drainage or where they’ll show up next, start with this question: What are they eating right now?

Spring (April–June): Recovery and Rebuild
Spring is about rebounding from winter. Deer are depleted, fawns are developing, and bucks are laying the foundation for antler growth. Their focus is on protein and soft green growth — early forbs and tender leaves.

In Wyoming and Montana, look for early green-up in foothills and sagebrush flats. In Idaho and western Colorado, focus on south-facing slopes. Top plants include desert parsley, spring phlox, arrowleaf balsamroot, tender sage tips, and early serviceberry leaves.

Summer (July–August): Antler Growth and Selective Feeding
This is peak antler growth season for bucks and lactation season for does. Forage is abundant, but mule deer are still picky. They target high-protein, mineral-rich forbs and shrubs like mountain mahogany, chokecherry, snowberry, serviceberry, lupine, and fireweed.

You’ll find bachelor groups feeding mornings and evenings in high basins (8,000–10,000 feet), bedding in shaded cover during the day. If you’re after velvet bucks, summer forage tells you exactly where they’ll be.

Fall (September–October): Transition and Pre-Rut Buildup
As temperatures drop, high-country plants dry up and deer move to mid-elevation brush zones. They shift toward woody browse like bitterbrush, cliffrose, mountain mahogany, serviceberry, and oak mast. In southern Colorado, acorns are a major fall food source.

Find a brushy bench below timberline with bitterbrush or serviceberry, and you’ll likely find daylight movement.

Winter (November–March): Survival Mode
By winter, everything is about conserving energy. In Wyoming and Montana, deer drop to wind-blown ridges and south-facing slopes where shrubs remain exposed.

They feed primarily on bitterbrush, sagebrush, cliffrose, rabbitbrush, and greasewood. These aren’t high in protein, but they’re digestible and available when nothing else is. Where these foods disappear, so do the deer.

Regional Forage by Elevation

High Elevation (8,000–11,000 ft)

Classic summer and early fall range for velvet bucks. Forage includes lupine, fireweed, bistort, false dandelion, paintbrush, serviceberry, snowberry, and young aspen shoots. Focus on basins with lush forbs near bedding cover.

Mid Elevation (6,000–8,000 ft)

Prime transition country. Key plants: bitterbrush, cliffrose, mountain mahogany, chokecherry, serviceberry, and snowberry. These zones produce the best fall hunting. Look for benches with mixed brush and nearby escape cover.

Low Elevation (3,500–6,000 ft)

Classic winter range. Mule deer rely on sagebrush, rabbitbrush, greasewood, four-wing saltbush, winterfat, and snowberry. Focus your glassing on south-facing slopes and windblown ridges where feed stays exposed.

State-Specific Highlights

Wyoming:
Bitterbrush and sage dominate. Serviceberry and mountain mahogany are key transition plants, especially in the Bighorns and western ranges. Focus where sage flats meet rimrock or brushy draws.

Montana:
Sagebrush and snowberry cover huge areas, with chokecherry and mahogany in the west. Eastern Montana deer rely heavily on winterfat and rabbitbrush. Focus on broken terrain with mixed brush and snowberry for mid-season success.

Idaho:
Southern and central Idaho are shrub-rich. Bitterbrush, cliffrose, and mahogany lead the list. Burns and avalanche chutes with snowberry regrowth are gold.

Colorado:
Oak brush, serviceberry, and mountain mahogany dominate the middle elevations. Cliffrose and chokecherry thrive in foothills. Focus on burn edges, oak transitions, and snowberry zones near cover.

Nutrition, Antler Growth & Behavior

Antler potential isn’t just genetics or low pressure—it’s nutrition.

Spring and summer protein sources build antler mass and body condition. Plants like lupine, serviceberry, and mahogany provide essential amino acids, calcium, and phosphorus. By late summer, mule deer shift toward carbohydrate-heavy browse like bitterbrush and cliffrose to bulk up for the rut.

After the rut, survival becomes the priority. Bucks rely on high-fiber shrubs like sage and snowberry to stay alive through harsh conditions. Fat reserves built in the fall determine not just winter survival, but next year’s antler growth.

Mule Deer vs Elk: Browsers vs Grazers

Elk are grazers—they eat grass and forbs in volume, often in open meadows. Mule deer are browsers, feeding on select shrubs, buds, and leaves in small quantities throughout the day.

That means mule deer spend more time in cover, feeding in short bouts between bedding sessions. They live in the feed rather than migrating to it, often staying within the same 1–2 square-mile home range year after year if the forage mix is consistent.

When pressure rises, elk might relocate. Mule deer simply tighten up and feed at night or in thicker pockets. Understanding this helps you hunt them smarter—focus on micro-movements, not mass herds.

Scouting and Glassing With a Forage Focus

Stop looking for deer. Start looking for what deer eat.

When e-scouting, begin with vegetation layers and satellite imagery. Identify south-facing slopes with sage, mahogany, or cliffrose. Locate snowberry patches near timberline or regenerating burns with serviceberry.

When glassing, ask yourself: Where can a mature buck feed unseen? Focus on brushy transitions—edges where bitterbrush meets slope or oak meets shadow. Deer feed in those shaded, overlooked zones far more than open hillsides.

Time your glassing around the forage curve:

  • Early season: high, green basins with forbs.

  • Mid-season: mid-elevation brush zones.

  • Late season: low, exposed sage and bitterbrush.

Habitat Change and Forage Decline

Modern mule deer face shifting diets due to grazing, urbanization, and invasive species.

Overgrazed public lands lose vital forbs and shrubs. Expanding subdivisions push deer into fringe zones—small patches of snowberry and cliffrose behind ag pivots or on the edge of towns. Invasive plants like cheatgrass, thistle, and knapweed choke out nutritious browse.

Hunters who learn to recognize these shifts gain a massive edge. Scout areas with ongoing habitat restoration or post-fire regrowth—years three through seven are prime for nutritious new forage.

The bottom line? When the forage declines, so do the deer. Find the feed first, and you’ll find the bucks.

Final Thoughts

If you’re still reading this far, you’re the kind of hunter who studies more than just sign—you study systems. Mule deer live and die by the land. The more you understand the plants that sustain them, the better you’ll become at finding and killing mature bucks year after year.

Train harder. Hunt smarter. Never settle.

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