Idaho Unit 31 Mule Deer Hunting Guide

Idaho Unit 31 is a mid-sized backcountry unit spanning 382,778 acres, with elevations ranging from 1,806 feet up to 7,562 feet — a spread that produces everything from low-elevation river breaks to high timbered ridgelines within the same unit boundary. For hunters researching Idaho Unit 31 mule deer hunting, this is a unit that rewards those willing to put in miles on foot, and the terrain diversity plays a direct role in how deer distribute themselves throughout the season.

With 52% public land, hunters have a majority-public unit to work with, though the remaining nearly half is private ground that will require permission or careful map study to avoid. This is not a unit where hunters can walk out any random gate and expect access — knowing exactly where public boundaries run matters as much as scouting deer sign itself.

Idaho's controlled hunt system means Unit 31 mule deer tags are allocated through the state's draw process rather than sold over the counter, and recent harvest data shows a unit that produces consistent, if modest, opportunity for hunters who draw a tag.

HuntPilot Analysis: Is Unit 31 Worth Applying For?

Unit 31 sits in a reasonable middle ground — not a slam-dunk unit, but a legitimate option for hunters who value backcountry solitude and are realistic about success rates. Harvest data over the past five years shows success percentages bouncing between 16% and 23%, which is a workmanlike range for a general mule deer unit rather than an elite trophy destination. The 2024 season was the strongest recent year, with 3,128 hunters producing 726 harvested deer for a 23% success rate. The 2022 season was the weakest, with 2,477 hunters and only 402 harvested animals for a 16% success rate — a reminder that conditions (snow, deer distribution, hunting pressure) can swing outcomes meaningfully year to year even within the same unit.

Trophy potential in the region overlapping Unit 31 is best described as moderate. The counties overlapping this unit carry a moderate history of producing record-book entries, which suggests hunters can encounter mature bucks here, but this is not a unit with an exceptional or heavily-documented trophy pedigree. Hunters chasing a genuine trophy-caliber buck should treat Unit 31 as a solid opportunity unit with occasional standout deer, not a unit where trophy production is the primary draw.

Where Unit 31 earns its keep is in the combination of acreage, elevation range, and majority-public access. A 382,778-acre unit with elevation spanning from below 2,000 feet to over 7,500 feet gives hunters real options to hunt different deer behavior patterns — lower-elevation deer that hold in breaks and drainages early, and higher-elevation deer pushed down by weather as the season progresses. For hunters willing to scout hard and hike, that terrain variety is a genuine asset.

Bottom line: Unit 31 is worth applying for if a hunter wants a public-land backcountry deer hunt with realistic, historically-documented success rates in the 16-23% range, and who is not solely chasing record-book bucks. It's a solid, honest unit rather than a bucket-list trophy unit.

Harvest Success Rates

• 2025: 2,841 hunters, 631 harvested, 22% success
• 2024: 3,128 hunters, 726 harvested, 23% success
• 2023: 2,782 hunters, 575 harvested, 21% success
• 2022: 2,477 hunters, 402 harvested, 16% success
• 2021: 1,010 hunters, 222 harvested, 22% success

A few things stand out. First, hunter numbers have grown substantially since 2021, nearly tripling from 1,010 hunters to over 2,800-3,100 hunters in the most recent three seasons. That's a meaningful increase in pressure, and it's worth factoring into scouting plans — more hunters on the landscape typically means deer get pushed harder and pattern changes happen faster once the season opens.

Second, success rates have remained fairly stable in the low-to-mid 20% range across four of the five years, with 2022 as the outlier low point at 16%. This consistency suggests Unit 31 is a dependable producer for hunters who do their homework, rather than a unit prone to wild boom-or-bust swings. A hunter drawing a tag here should reasonably expect success odds in the same neighborhood as the historical average — call it roughly one-in-five to just under one-in-four hunters filling a tag in a given year.

Trophy Quality

Trophy production in the counties overlapping Unit 31 carries a moderate history of record-book entries. This means mature bucks have come from this general region historically, but it is not a unit defined by frequent or exceptional trophy output. Hunters should view Unit 31 as a place where a genuinely good buck is possible, especially for those willing to get well off any road and hunt the more remote high-elevation pockets late in the season, but should not plan a hunt around the expectation of an all-time-caliber deer. As with any unit, trophy-class bucks are the exception rather than the rule, and most hunters here should set expectations around a solid, mature buck rather than a record-book wall-hanger.

It's worth noting that trophy records are logged at the county level and shared across all units within those counties — so any trophy history associated with this region reflects deer taken anywhere within the overlapping counties, not necessarily within Unit 31's exact boundary. Neighboring units draw from the same pool of historical entries.

Access & Terrain

Unit 31 covers 382,778 acres with an elevation range from 1,806 feet to 7,562 feet — one of the more dramatic elevation spreads a hunter will find in a single Idaho deer unit. That range matters practically: early in the season, deer are likely to be found using the full elevation gradient depending on weather, while later hunts can see deer pushed down out of the highest country as temperatures drop and snow accumulates at the upper elevations.

Public land in Unit 31 sits at 52%, meaning just over half the unit is open to public access while the remainder is privately held. This is a workable public-land percentage but not an overwhelming one — hunters need to identify exactly where public and private boundaries fall before committing to a specific drainage or ridge system. With no wilderness acreage recorded for this unit, there are no wilderness-specific access restrictions to plan around, and the terrain instead breaks down into standard public multiple-use and private ground.

Given the size of the unit and the mix of low-elevation river-adjacent terrain up through high timbered ridgelines, hunters should expect a genuine backcountry hunt requiring physical effort. Hunters who have posted about hunting Unit 31 describe covering significant ground away from roads to consistently encounter deer, with better sightings the farther hunters get from vehicle access points. This lines up with the general pattern in heavily-hunted public units — pressure concentrates near easy access, and deer respond by holding in the harder-to-reach terrain.

Hunters planning to scout Unit 31 should lean on mapping tools that clearly delineate the public/private boundary given the 52% public land split, and should use elevation-band overlays to identify where deer are likely to be holding based on time of year and weather. HuntPilot's mapping tools, including public land overlays and the ability to save pins on specific drainages or glassing points, are useful for breaking down a unit this large before ever setting boot to ground.

How to Apply

Idaho Unit 31 mule deer tags are allocated through Idaho's controlled hunt draw system, which — unlike several neighboring western states — operates as a straight lottery with no preference or bonus point system. Every applicant, whether applying for the first time or the twentieth, has the same odds on a given application in a given year. There is no point-building strategy in Idaho; the only lever hunters have is which hunts they choose to apply for.

Because Idaho's draw is a pure lottery with no points system, hunters should not expect improved odds by applying repeatedly in prior years — each year's draw is independent. For current draw odds specific to Unit 31, hunters should check HuntPilot's Idaho state page at /states/id or the Idaho Fish and Game Hunt Planner for the most current data.

Application dates and fees change every draw cycle. For the current deadlines, fees, and draw odds, see HuntPilot's Idaho page at /states/id.

Frequently Asked Questions

What is the terrain like in Idaho Unit 31? Unit 31 features a dramatic elevation range from 1,806 feet to 7,562 feet across 382,778 total acres, meaning hunters can encounter everything from low-elevation river breaks to high timbered ridgelines within the same unit. With 52% public land, roughly half the unit is open to public access, while the remainder is private — hunters need to carefully map the public/private boundary before planning a hunt.

What is harvest success like in Idaho Unit 31? Recent harvest data shows success rates ranging from 16% (2022) to 23% (2024) over the past five seasons, with most years landing in the 21-23% range. Hunter numbers have increased substantially since 2021, growing from roughly 1,000 hunters to over 2,800-3,100 hunters in recent years, which is worth factoring into pressure expectations.

How big are the deer in Idaho Unit 31? Trophy potential in the counties overlapping Unit 31 is moderate — there is some history of record-book bucks coming from the broader region, but it is not a unit known for frequent or exceptional trophy production. Hunters should expect a realistic chance at a mature buck, with true trophy-class deer being the exception rather than the norm.

Is Idaho Unit 31 worth applying for? For hunters seeking a public-land, backcountry-style mule deer hunt with historically consistent (if modest) success rates and a genuine physical challenge, yes — Unit 31 is a solid option. It is not, however, a unit defined by exceptional trophy production, so hunters chasing a record-book buck specifically should weigh that against the unit's moderate trophy history before applying.

Does Idaho use a preference point system for Unit 31 deer tags? No. Idaho's controlled hunt draw is a pure lottery with no preference or bonus points. Every applicant has identical odds each year regardless of how many times they've applied previously — there is no point-building strategy to employ in Idaho's system.