Bitterroot Range

Mountains Mountain range forming Idaho–Montana border with rugged peaks

A rugged mountain chain along the Idaho-Montana border, the Bitterroot Range draws hikers, backpackers and anglers to alpine trails, river canyons and backcountry camping amid conifer forests and steep ridgelines.

Main image

The Bitterroot Range is a subrange of the Rocky Mountains that runs along the border between Idaho and western Montana. It is part of the northern Rocky Mountain chain and contains extensive forested and alpine terrain.

Alpine ridges, glacier-scoured cirques and numerous trails draw hikers, climbers and backcountry users; the range includes long stretches of remote wilderness and designated areas for recreation and conservation. Key features include high peaks, steep river valleys and large tracts of national forest.

Geologically the range was uplifted as part of the Rocky Mountains and was later sculpted by glaciation; human use has included traditional use by Indigenous peoples, followed by hunting, timber harvest and recreation. Large portions are now managed for conservation and public access.

Geographically the range straddles north-south between central Idaho and western Montana, rising above valleys such as the Bitterroot Valley to the east and river systems to the west, and is accessed from towns on both sides of the border.

  • Location and protection: The range forms a significant portion of the border region between Idaho and Montana and is covered by extensive national forest lands and designated wilderness.
  • Highest point: Trapper Peak is the range's highest summit at 10,157 feet (3,094 meters), and it is a common objective for hikers seeking panoramic views.

What to See #

  • Selway-Bitterroot Wilderness: A large federally protected wilderness area that covers much of the central Bitterroot Range and adjoining lands, providing long-distance trails, backcountry campsites and roadless terrain.
  • Bitterroot Valley: A broad agricultural valley running along the eastern flank of the range that provides common trailheads and town services for access into the mountains.
Bitterroot Range
46.7355, -115.4076
Open access
Free (open access)

Tips for Visiting Bitterroot Range #

  • Most trail access comes from the Bitterroot Valley on the west side - towns such as Hamilton and Darby serve as practical bases with parking and trailhead access to western approaches.
  • Avoid busy summer weekends by starting alpine hikes very early or choosing midweek; for any multi‑day routes consult the Bitterroot National Forest ranger station for current trail, river‑crossing and bear‑activity information.

Best Time to Visit Bitterroot Range #

The best time to visit the Bitterroot Range is summer through early fall (June-September) for the most reliable trail and road access.

Summer (best for outdoor access)
June-September · 5-25°C (varies strongly with elevation)
Warmest and most accessible period for hiking, backpacking and road access; higher ridges remain cool.
Shoulder seasons
May, October · 0-15°C
Cooler, more variable weather with fewer visitors; early snow or late-season storms can affect higher areas.
Winter
November-March · -15-5°C
Cold with significant snowfall in many areas-many routes and passes may be impassable without winter gear and experience.

Weather & Climate near Bitterroot Range #

Climate

Bitterroot Range's climate is classified as Subarctic (Dry Summer) - Subarctic (Dry Summer) climate with cool summers (peaking in August) and freezing winters (coldest in January). Temperatures range from -12°C to 23°C. Moderate rainfall (649 mm/year).

Temperature & Rainfall
Temperature Range
23°
Warmest Month
-12°
Coldest Month
Monthly Conditions

January

January is the coldest month with highs of -1°C and lows of -12°C. The wettest month with 78 mm of rain.

Comfort

-7°
Feels Like Freezing
-7°C
Temperature
-12° -1°

Weather

78 mm
Rainfall
2.9 m/s
Wind
Calm

February

February is freezing with highs of 1°C and lows of -12°C. Moderate rainfall (52 mm).

Comfort

-5°
Feels Like Freezing
-5°C
Temperature
-12°

Weather

52 mm
Rainfall
2.7 m/s
Wind
Calm

March

March is freezing with highs of 3°C and lows of -9°C. Moderate rainfall (55 mm).

Comfort

-3°
Feels Like Freezing
-3°C
Temperature
-9°

Weather

55 mm
Rainfall
3.0 m/s
Wind
Light Breeze

April

April is cold with highs of 6°C and lows of -6°C. Moderate rainfall (51 mm).

Comfort

Feels Like Cold
C
Temperature
-6°

Weather

51 mm
Rainfall
2.9 m/s
Wind
Calm

May

May is cold with highs of 11°C and lows of -2°C. Moderate rainfall (60 mm).

Comfort

Feels Like Cold
C
Temperature
-2° 11°

Weather

60 mm
Rainfall
2.9 m/s
Wind
Calm

June

June is cold with highs of 16°C and lows of 2°C. Moderate rainfall (61 mm).

Comfort

Feels Like Cold
C
Temperature
16°

Weather

61 mm
Rainfall
2.9 m/s
Wind
Calm

July

July is cool with highs of 22°C and lows of 4°C. The driest month with just 25 mm.

Comfort

13°
Feels Like Cool
13°C
Temperature
22°

Weather

25 mm
Rainfall
2.8 m/s
Wind
Calm

August

August is cool with highs of 23°C and lows of 3°C. Moderate rainfall (38 mm).

Comfort

13°
Feels Like Cool
13°C
Temperature
23°

Weather

38 mm
Rainfall
2.7 m/s
Wind
Calm

September

September is cold with highs of 18°C and lows of 0°C. Moderate rainfall (44 mm).

Comfort

Feels Like Cold
C
Temperature
18°

Weather

44 mm
Rainfall
2.7 m/s
Wind
Calm

October

October is cold with highs of 11°C and lows of -4°C. Moderate rainfall (49 mm).

Comfort

Feels Like Cold
C
Temperature
-4° 11°

Weather

49 mm
Rainfall
2.8 m/s
Wind
Calm

November

November is freezing with highs of 3°C and lows of -8°C. Moderate rainfall (66 mm).

Comfort

-3°
Feels Like Freezing
-3°C
Temperature
-8°

Weather

66 mm
Rainfall
3.0 m/s
Wind
Light Breeze

December

December is the coldest month with highs of -1°C and lows of -12°C. Moderate rainfall (70 mm).

Comfort

-7°
Feels Like Freezing
-7°C
Temperature
-12° -1°

Weather

70 mm
Rainfall
2.8 m/s
Wind
Calm

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