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Insane Idaho/Montana Border Roller Coaster of the CDT

Insane Idaho/Montana Border Roller Coaster of the CDT

This post talks about the Idaho/Montana border section of the CDT.  Depending on the route choices made, the CDT follows this state border for almost 300 miles. 

You think the roller coaster on the AT was hard?  Just wait until the Idaho/Montana border.  Then, add grizzlies. 

Read on for my hiking strategy through this section of trail AND for some pro tips.

This post contains affiliate links.  I have used every product mentioned and if you purchase one of these products I can make a small commission at no cost to you.

Basic Low-Down on the Idaho/Montana Border of the CDT

The Idaho/Montana border section of the CDT runs between Yellowstone National Park and Chief Joseph Pass. 

Two main route choices within this section exist.  First, the official route follows the divide around Henry’s Lake just west of Yellowstone.  Second, the Mack’s Inn Cut-Off saves about 40 miles and runs south of Henry’s Lake. 

In more recent years, the Henry’s Lake route has increased in popularity.  However, it has one major downside.  To resupply, you have to hitch hike into West Yellowstone.  Not only is West Yellowstone incredibly touristy, but hitch hiking is also *technically* illegal in Idaho.  On that section of Highway 20, the cops know people hitch there.  They sit there and wait for you.

Other than those two route options, the Idaho/Montana border section of the CDT runs ridges.  Ridges all day and all night.  Why?  Because that’s the divide.

Because the trail runs the tops of the ridges, water gaps increase along with exposure to wind.

Campsite on the Idaho/Montana Border
Our SMD Tarp & Bug Net on the border ridge

Why is it a Roller Coaster?

I call this section a roller coaster for several reasons. 

First, the trail takes you up and down over ridge after ridge.  It has many longer climbs and descents to ascend and descend each ridge.

Second, almost none of those ridges are flat.  Most of them have 200-500ft climbs on top of them.  This means that once you get up on a ridge, you’ll be hiking up and down along the spine.  Some have more ups and downs than others.

Third, if a thunderstorm races up, you’ll likely have to run off the side of a ridge for shelter.  Thus, giving you an extra up and down. I write more on thunderstorms on the CDT in my Colorado post and in Is the CDT Dangerous.

Large open ridge with a route atop it.
Border Ridgeline

My Idaho/Montana Resupply Strategy

The Idaho/Montana Border section has limited resupply options. Towns are small and far apart.

I have thru-hiked the CDT twice, once southbound and once northbound.  I have used the same strategy both times.  Why?  Because, it works.

Since I most recently hiked northbound, I’ll detail my strategy that direction.  However, you can easy flip it.

I also found the ALDHA West CDT resupply strategy page helpful for this 2022 hike.

Mack’s Inn

I almost always prefer a walk in/walk out resupply.  Why?  I am only beholden to my schedule.  As much as I enjoy hitch hiking, the variability stresses me if I’m short on time.  For example, if I’m pushing to get Saturday post hours, I want to know that I will make it. 

Lima, MT

Lima is one of the tiniest towns on trail.  However, with a little planning, it works easily and efficiently.  Mike and Connie at the Mountain View Motel offer an affordable rate and a donation-based shuttle.  They have overflow camping if all the rooms are taken.  Also, they have just a shower and laundry option if you don’t want to stay. 

However, SEND A PACKAGE HERE.  Especially if you have ANY dietary restrictions. Vegans, I am talking directly to you.  The gas station resupply gets stretched THIN.  The southbound and northbound bubbles converge here creating a lack of food in the gas station.

You could get a ride up to Dillion, MT for a solid grocery store.  But, it’s on i-15 so beware of hitching on interstates. Along the Idaho/Montana border, it’s not always clear what state you’re in, even on the roads.

Leadore, ID

In more recent years, traffic has increased at Bannock Pass.  Trail angels have also cropped up for donation-based rides.  Not only does the town have a camping option, you can schedule rides in and out of the town in the same day. 

However, same as Lima, SEND A PACKAGE HERE.  Especially if you have any dietary restrictions.  The store has a bit more inventory than the Lima gas station, but not by much.  It also tends to fall in the northbound and southbound bubble convergence.

Darby, MT

I like to pull the long section from Leadore to Darby (from Chief Joseph Pass).  You could also send a package to Sula or hitch all the way to Salmon.  However, I feel like Darby is a very efficient town. 

It has a grocery store that is legit after the previous two stores.  Resupplying here has good options for food and decently priced accommodations.

For most people, the hitch either way doesn’t take more than 30 minutes.  Obviously, outliers exist.  But, most people do not complain about this hitch.

Wait, I Have to Pay Attention to Water Again?

Through most of this section gaps of 8-20 miles exist between water sources.  So, yes, you have to pay attention to water again.

Importantly, the Idaho/Montana border section rides ridges.  Water sources tend NOT to reside on the top.  This means that thru-hikers must often go off trail, downhill to a water source. 

Moreover, the distance to off-trail water sources increases as well.

If you carefully pay attention to Far Out, you can see the water distances and plan accordingly.  Sometimes, water exists on other icons like junctions. 

Personally, I try to find the best water sources that occur closest to trail.  Sometimes, I will carry extra to not hike ½ mile off trail and a ½ mile back. 

This Piped Water Source was 100 yds Off-Trail
This Piped Water Source was 100 yds Off-Trail

Grizzlies on the Idaho/Montana border

Grizzly bears are concentrated mostly around Yellowstone National Park, Glacier National Park, and the Bob Marshall Wilderness.

However, the entire corridor between Yellowstone and Glacier is grizzly habitat. 

While not as common, they still exist and thru-hikers should not become complacent. 

Thru-hikers should still carry bear spray, but it should only be used as a last resort.


This section is hard mentally and physically.  It takes a toll mentally for northbounders realizing just how much trail is left.  For southbounders, you’re ready to get out of Montana already!

The resupply options can also deplete a thru-hiker along the Idaho/Montana border.  For example, you might get to Lima and get stuck with gummy bears as your snacks.  Those offer no nutrition at a time when the body desperately needs good calories. 

Basically, this section just needs a little more planning than others.  I hope this helps you!