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Lost River Expedition

 4.0 (2)
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Map Key

69.5 Miles 111.9 Kilometers



11,172' 3,405 m


-11,174' -3,406 m



Avg Grade (3°)


Max Grade (27°)

10,461' 3,189 m


6,967' 2,123 m


Shared By Chris Wandervans



Getting forecast...

A big bikepacking epic out in the middle of nowhere.

Chris Wandervans

Dogs Off-leash

Features -none-

Can be snowbound until July.


An epic bikepacking trip out in the middle of nowhere that will test your hiking and route finding skills. The views are epic and the terrain is daunting!

Need to Know

This is a multi-day bike pack trip that is best done over three days and two nights. There is water in the mountains, but once out into the sagebrush hills moisture gets very scarce. There will also be lots of hike-a-biking up in the passes, so you'll want to pack light.


This ride can be ridden in either direction, but this route has you traversing the flat areas in front of the mountains and then climbs you through the passes. You'll start on the Long Lost-Wet Creek Trail and then turn onto the Massacre Mountain trail which will end at the Massacre Creek trail. From here, you'll work your way across the front of the range on a network of BLM and ranch roads, There are lots of false tracks, so take your time finding your way. In the flatlands, it is best to have the MTB Project mobile app handy so that way you can keep an eye on all the turns. Only the major drainages will have water, so keep that in mind as you work your way across.

You'll work through a number of drainages before coming to the East Fork Upper Pahsimeroi drainage and eventually the trail itself. The trail is rideable for a ways until it becomes steep and then you'll be off your bike as you go up and over the pass in the Dry Creek drainage. Down the Dry Creek drainage, you'll go to the Swauger Lake Trail. This will then climb you back into the mountains and over the ridge. You'll then descend into the Long Lost drainage and climb up to your next pass where you'll then descend. Drop off this steep pass on the Long Lost-Wet Creek trail and will follow this back to your car.

This ride starts near the Pass Creek Rd so it is easier to access than having to drive the long way around Arco. You can certainly access this ride at any point, but this is the most reasonable location. There is also some car camping near the start so that way you can get an early start in the morning.

This ride is best done in July or early August and you'll need to beware of thunderstorms. Since a lot of the ride is above treeline, you can be very exposed if something comes in over the mountains. Most of the storms will be coming from the west, so it is best to keep a keen eye pointed in that direction.


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  4.0 from 2 votes


  4.0 from 2 votes
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in Idaho


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Anonymous User
Anonymous User  
Amazing route and very challenging. I have to say that the description is a little bit of a sandbag though. Getting over the mountain passes is very serious and I wouldn't call it "hike-a-bike". The only thing I can call it with a straight face is "3rd class mountaineering holding a bicycle". If you dont know what 3rd class mountaineering is, you shouldn't do this route... Jul 27, 2016
Anonymous User
Anonymous User  
I added a hazard marker to the map showing the most serious section. Proceed with care. Jul 27, 2016

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