Official Government Website
PARK UPDATE:
  • Spring trails are now open; the $6 winter access fee has ended for the season.
  • The $7 per-vehicle MVEF (Motor Vehicle Entrance Fee) remains in effect.
  • Seasonal trail closures (April 15–June 15) for waterfowl nesting:
    • Affected segments run from the North Gate to the John Muir Trail along the Henrys Fork River, near the bird sanctuary.
  • Construction notice (May – October):
    • Harriman State Park sewer and waterline construction start date: May 22, 2025. Work continues through fall. Although only yurts are available for overnight rentals during this time, day-use facilities and trail access will be open to the public. When in the park, please observe any posted signage, caution tape, construction cones, or directions from Park staff about construction areas. You may be re-routed to access a trail, and parking lot areas may be limited due to the construction.
    • Be advised that the primary location for restrooms will remain the Park’s vault toilets, as well as 4 porta-potties. These will be located at the Visitor Center and Boys House in the historic district. As waterlines will be affected by the construction, water fountains will not be operational. Please make sure to bring plenty of drinking water to use while enjoying the park. Thank you for your patience during our improvement to your State Park!
    • The Boys House remains open as a family gathering space.
  • Dog policy:
    • Dogs allowed only in parking lots; no summer‑season trail access.
    • Must be on a six‑foot leash and attended at all times; stray or unattended animals may be impounded at owner’s expense (IDAPA 26.01.20.175.09).
  • Bear‑aware reminders:
    • Make noise, travel in groups, stick to daylight hours.
    • Carry bear spray and a bell.
  • Follow our Facebook page for the latest trail conditions, upcoming events, and a link to local weather.
Park Reservations
By phone: 1-888-9-CAMPID or 1-888-922-6743

Mesa Falls Recreation Area is owned by the US Forest Service and co-managed by Harriman State Park.

Summer/Spring

Big Falls Inn, an interpretive building and store, is open from Memorial weekend to mid-September from 9:30 a.m. to 5:30 p.m.

Winter

In the winter, Scenic Byway 47 does not remain open to vehicles but is groomed for snowmobile traffic. The falls are only accessible by snowmobile or cross-country skies and visitors can park at Bear Gulch on Scenic Hwy 47 east of Ashton and ski or snowmobile the packed road 5 miles to Mesa Falls. Snowmobilers can also reach Mesa Falls from Hwy 20 via Scenic Byway 47, which is a 14-mile scenic ride. 

More Information

Current Conditions

Contact the Park

Address: 3489 Green Canyon Rd
Island Park, ID 83429
Phone: (208) 558-7368
Hours of Operation: Day-use locations within state parks are open from 7 am to 10 pm, per Idaho state code 26.01.20 (5). Day-use hours may change based on park manager discretion.

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