Hagerman Fossil Beds National Monument

Park National monument preserving Pliocene fossil beds

Hagerman Fossil Beds National Monument preserves Pliocene fossil beds in Idaho, notable for the Hagerman horse remains; visitors use the center, trails and interpretive signs to explore local paleontology.

Main image

Hagerman Fossil Beds National Monument is a protected paleontological site in south-central Idaho that preserves extensive Pliocene fossil deposits. It is best known for rich vertebrate fossil assemblages, including the well-documented Hagerman Horse.

Fossil discoveries in the Hagerman area began in the early 20th century and led to systematic paleontological work that established the scientific importance of the deposits. The site was later protected to preserve its fossil resources and to allow research and public education about the Pliocene fauna of North America.

The monument lies on the southern bank of the Snake River near the small town of Hagerman in south-central Idaho. The surrounding landscape is river valley and semi-arid plain, with the nearest regional service centers located in other communities of south-central Idaho.

  • Age and fossils: The site preserves Pliocene-age fossil beds that are roughly 3 to 4 million years old and are noted for abundant vertebrate fossils including multiple specimens of the Hagerman Horse.
  • Visitor note: Trails are short and interpretive; the visitor center provides the main fossil displays and is the best first stop for orientation and ranger programs.

What to See #

  • Visitor Center and exhibits: A visitor center with interpretive exhibits that explain the Pliocene fossil record of the region, local geology, and displays of the Hagerman Horse and other recovered specimens.
  • Fossil beds and trails: Exposed fossil-bearing deposits and a network of short trails along the Snake River that provide access to viewing areas and interpretive stops about the paleontology of the site.
Hagerman Fossil Beds National Monument
Hagerman Fossil Beds National Monument, Idaho, USA
42.7907, -114.9443
Open year-round; visitor center seasonal
No entrance fee

Tips for Visiting Hagerman Fossil Beds National Monument #

  • Begin at the Hagerman Fossil Beds visitor center to learn which trails and overlooks are open and where interpretive displays and viewing areas are located.
  • Spring and fall offer the most comfortable conditions for exploring the badlands and photography-expect hot summers and cold winters in this part of Idaho.
  • Fossil excavation is not open to the general public-ask rangers about public viewing spots, exhibits, and any ranger-led programs before heading onto trails.

Best Time to Visit Hagerman Fossil Beds National Monument #

The best time to visit Hagerman Fossil Beds National Monument is late spring through early fall when trails and services are most accessible and weather is milder.

Late spring to early summer
Apr-Jun · 5-25°C
Trails and roads are usually open, with mild weather ideal for outdoor walks and fossil‑site viewing.
Summer
Jul-Aug · 15-35°C
Warmer and drier conditions; daytime heat can be strong, so plan outdoor activities for mornings or late afternoons.
Fall
Sep-Oct · 5-20°C
Cooling temperatures and generally good access - another excellent period for hiking and site exploration; winter can bring snow and limited access.

Weather & Climate near Hagerman Fossil Beds National Monument #

Climate

Hagerman Fossil Beds National Monument's climate is classified as Cold Desert - Cold Desert climate with warm summers (peaking in August) and freezing winters (coldest in January). Temperatures range from -7°C to 34°C. Very dry conditions with minimal rainfall.

Temperature & Rainfall
Temperature Range
34°
Warmest Month
-7°
Coldest Month
Monthly Conditions

January

January is the coldest month with highs of 3°C and lows of -7°C. Moderate rainfall (30 mm).

Comfort

-2°
Feels Like Freezing
-2°C
Temperature
-7°

Weather

30 mm
Rainfall
3.0 m/s
Wind
Light Breeze

February

February is cold with highs of 7°C and lows of -5°C. Light rainfall.

Comfort

Feels Like Cold
C
Temperature
-5°

Weather

23 mm
Rainfall
3.3 m/s
Wind
Light Breeze

March

March is cold with highs of 13°C and lows of -1°C. Light rainfall.

Comfort

Feels Like Cold
C
Temperature
-1° 13°

Weather

26 mm
Rainfall
3.7 m/s
Wind
Light Breeze

April

April is cold with highs of 18°C and lows of 1°C. Light rainfall.

Comfort

10°
Feels Like Cold
10°C
Temperature
18°

Weather

17 mm
Rainfall
4.0 m/s
Wind
Light Breeze

May

May is cool with highs of 23°C and lows of 6°C. Light rainfall.

Comfort

14°
Feels Like Cool
14°C
Temperature
23°

Weather

22 mm
Rainfall
3.7 m/s
Wind
Light Breeze

June

June is mild with highs of 28°C and lows of 10°C. Light rainfall.

Comfort

19°
Feels Like Mild
19°C
Temperature
10° 29°

Weather

18 mm
Rainfall
3.5 m/s
Wind
Light Breeze

July

July is mild with highs of 34°C and lows of 12°C. The driest month with just 6 mm.

Comfort

23°
Feels Like Mild
23°C
Temperature
12° 34°

Weather

6 mm
Rainfall
3.2 m/s
Wind
Light Breeze

August

August is the warmest month with highs of 34°C and lows of 12°C. Almost no rain.

Comfort

23°
Feels Like Mild
23°C
Temperature
12° 34°

Weather

8 mm
Rainfall
3.0 m/s
Wind
Light Breeze

September

September is cool with highs of 28°C and lows of 7°C. Light rainfall.

Comfort

18°
Feels Like Cool
18°C
Temperature
28°

Weather

13 mm
Rainfall
2.9 m/s
Wind
Calm

October

October is cool with highs of 21°C and lows of 2°C. Light rainfall.

Comfort

11°
Feels Like Cool
11°C
Temperature
21°

Weather

17 mm
Rainfall
3.0 m/s
Wind
Light Breeze

November

November is cold with highs of 11°C and lows of -2°C. The wettest month with 34 mm of rain.

Comfort

Feels Like Cold
C
Temperature
-2° 11°

Weather

34 mm
Rainfall
3.0 m/s
Wind
Light Breeze

December

December is freezing with highs of 4°C and lows of -6°C. Light rainfall.

Comfort

-1°
Feels Like Freezing
-1°C
Temperature
-6°

Weather

28 mm
Rainfall
3.1 m/s
Wind
Light Breeze

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