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Level: Intermediate
Length: 26 mi (41.8 km)
Surface: Singletrack
Configuration: Loop
Elevation: +1,008/ -1,065 ft
Total: 17 riders

Mountain Biking Harrington Fork

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#29 of 316 mountain bike trails in Idaho
#3,007 in the world

From the parking area go east on the singletrack by the bathroooms. The trail starts with an 8mi climb on thight sometimes loose singletrack, there are alot of weeds on the sides of the trail that will get caught in your drivetrain. After are a few stream crossings, that were dry when I went, there is a livestock fence to go through. After crossing a couple of jeep roads at the top and going through another livestock fence, continue on the trail for a decent into the next valley. At the bottom be ready for another climb of about 4mi. Decend on Triple Fork trail for about 8mi to its trailhead. Here you will have to go to your right out of the parking area for a ride on the road back to Harrington Fork parking area, about 4mi.

First added by ameyer on Aug 20, 2004. Last updated Apr 30, 2020. → add an update
Before you go
  • Drinking water: unknown
  • Lift service: unknown
  • Night riding: unknown
  • Pump track: unknown
  • Restrooms: unknown
  • Fat bike grooming: unknown
  • E-bikes allowed: unknown
  • Fee required: unknown
This trail information is user-generated. Help improve this information by suggesting a correction.
Getting there
From Twin Falls, go south on Blue Lakes Rd to Kimberly Rd, go east on Kimberly Rd for about 7mi to Rd G3, there is a sign for Rock Creek befor the turn, go south for 20mi on Rd G3 through Rock Creek and into the Sawtooth National Forest area to the Harrington Fork picnic parking area on your left, there is a sigh designating this parking area.
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(on Jan 31, 2023)
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  • frogge

    This is a really great trail. No gradients that couldn't be managed with a single speed. Nothing super technical, although there are a few spots on the decent that will get your attention. There were some blow downs that were somewhat challenging to navigate around. The Topo on this sight was helpful to keep from getting lost. This trail is known as the Nirvana loop and when I rode it it lived up to its name. It is listed as expert, but if you are in good shape and use reasonable care can be ridden by strong intermediate riders.

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  • asparks65

    If you start from the lower trailhead its a long grinding climb for 7-8 miles. It was very dry when I rode there and the soil was so dry it was powder and climbing was difficult in many spots. Go to one of the campgrpunds and get a free map from one of the campground hosts. There are MANY miles of ATV trails that are fast and flowy. I camped at Porcupine and had a blast on the double track ATV trails for 2 days of riding

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  • harryhoodlum

    This is also known as the Nirvana Loop. If you like smooth continuous singletrack riding, you'll love this ride. Most will probably need a guidebook or detailed directions from a local bike shop since there are many junctions with double track roads and unmarked turns. Briefly the trail follows Harrington Fork up ~7 miles than drops into the First Fork drainage. Follow First Fork trail up and onto plateau where you will continue south for a few more miles before coming to the Martindale fork trail which will start your long descent. Summer on 2011 brought some changes to Martindale fork to widen it in parts for the use of 4-wheelers. Too bad. Martindale fork ends at Third fork trail which you follow to the bottom and Rock Creek paved road. Follow this down to your car that you parked at Harrington fork trailhead

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  • sethspringer12

    I rode this on one of the last days to ride in November. It was a great trail and not as steep as I was thinking. It does have quite a bit of up hill and I only had an hour, so I made it about 4 miles. Watch out for the cow carcass off to the left side of the trail about 3 miles up. It is a great ride tho.

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  • adrougas

    The "aromatic" aspen groves are quiet unique on this trail. At times the odor was almost overpowering! The uphills are challenging for early-season riding (endurance issues mostly on long but manageable uphills), the trails are good confidence-builders (wide, well-packed, fast and open), the difficulty technically on any one portion of the ride is moderate. This is definitely an Idaho gem, would advise in early season due to temperature issues. Estimate of average annual opening of trails: Mid-May.

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