Yellowstone: South Boundary Trail to Thorofare Valley

September 08, 2023  •  7 Comments

We just got back from our 6-day, 78-mile trip into Yellowstone's Thorofare. It's touted as the most remote location in the contiguous 48 states. There are three trails that lead you to the area starting in the park, and the shortest trail is about 32 miles one way. This is the longest trip, both in duration and length that I have ever done. 

After years of talking about it, and then six months of planning it, the week finally arrived. The weather looked clear but windy for the first few days, then starting to deteriorate after that. Our plan was to catch a shuttle across the lake to Terrace Point, then hike south into the Thorofare and back to our car at the South Entrance via the South Boundary Trail. Here's how it went.

Day 1: 12.5 miles, 1,415 ft elevation gain

We loaded up our gear on the boat and set off from Bridge Bay Marina. After about 30 min on the water, that "clear but windy" weather made it clear to us that we weren't getting across the lake today. So after turning around we debated our options back on shore. We decided that we wanted to take shuttles/hitchhiking out of the equation, so we changed our itinerary and would hike in and out via the South Boundary Trail. That means our 55-mile trip would now be closer to 80.

By the time we made it back to the South Entrance and set off, it was 1pm. We forded a clear Snake River and hiked through a mostly nondescript landscape for the first 6 miles. Eventually we reached an open meadow where we met up with the Snake River again and Snake Hot Springs.

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Eventually we came across our second and last river crossing for the day. We took a break along the river before hiking the final two miles to our camp.

20230830-jwf-046320230830-jwf-0463NPS / Jacob W. Frank

Day 2: 12.25 miles, 3,001 ft elevation gain

With our late arrival in camp the night before, we didn't get hiking until about 9am. Today was supposed to be the most challenging day of the trip. The hike over Big Game Ridge takes you in and out of the park and offers views all directions when you're over 10,000 ft elevation. The weather was perfect, not a cloud in the sky, which also meant that we were exposed. 
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Eventually we gained enough elevation where we could see the Tetons to the south starting to rise up from the hills.

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Once we gained the ridge, the views of the Grand and the entire Teton Range were spectacular.

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We continued along the ridge with more spectacular views to the north and east, including Heart and Yellowstone lakes, the Absaroka Range, and even Electric Peak.

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Just before we started to descend, we decided to grab lunch with a good view.

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Eventually we made it off Big Game Ridge and were back to another crossing of the Snake River, just before we reached our spot for the night.

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Day 3: 14.25 miles, 2,202 ft elevation gain

I woke up with a sore hip flexor, which isn't uncommon for me when backpacking. When we set off it took a little adjusting to get my pack in a comfortable spot. After walking for about 5 minutes, my hip/leg muscles were tighter than I thought. I stretched for 10 minutes, and I realized that my hip felt fine as long as I didn't have my pack's hip belt on tight. It was great I figured that out, but not great to realize that I was going to have to hike the day with a pack without using my hip belt.

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We gained our way through the woods and eventually to Mariposa Lake.

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As we continued east, we started to descend along Lynx Creek. There were many small water and bog crossings. In the mud we started seeing lots of bear tracks, both big and small, black and grizzly. At one point along the trail while making noise, we both were hit with the smell of a rotting carcass. We both immediately picked up the pace until we were out of the area and could no longer see any tracks. (More on this during the following day)

20230901-jwf-077620230901-jwf-0776NPS / Jacob W. Frank

After about mile nine we could finally see the mountains to the east of the Thorofare Valley. 

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At mile 10 we made our way to the valley floor and stopped to rest before we had to ford the Yellowstone.

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After scouting a few options, we found a good spot to ford that was only over our knees.

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After a few more miles we finally made it to our destination, the Thorofare Ranger Station. We had seen photos of it, but it was pretty cool to see in person. We also explored the barn and the most remote outhouse. 

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We hung out on the porch, reading the visitor log of those who made the trek before us, waiting for the sun to set.

20230901-jwf-093120230901-jwf-0931NPS / Jacob W. Frank

Day 4: 14.25 miles, 2,340 ft elevation gain

Now that we had hike the 39 miles to get out here, we were only half way. In our initial plan we were supposed to have a layover day in the Thorofare, but with the new itinerary we would be hiking every day. So we woke up early so we could take in the sunrise before starting our 14 mile day. This morning I noticed that in addition to my hip, my achilles was swollen and it was hard to get my boot on. No biggie, we only had 39 miles to go. Corrie offered to take extra weight and put me on the "mountain skittles" (ibuprofen) regimen to keep the swelling down.

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We hiked back across the valley taking in the views, which were spectacular.

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On our way back across the Yellowstone, the wind had died down from the previous afternoon so much that we were greeted to a nice reflection.

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I mentioned earlier that the previous day we had hiked near a carcass on the trail. On our way back through we were expecting to come across the same smell but didn't. So our guess is that it wasn't a carcass, but more likely a bear that we hiked past. Bears, especially grizzlies, can be very smelly. Since we were seeing lots of tracks and scat in the area where the smell was, and there was no smell the following day, we think there was probably a bear in the area. Eventually we made the climb back out of Lynx Creek to our camp, where we could see tomorrow's objective, Big Game Ridge, rising above the trees in front of us.

20230902-jwf-108420230902-jwf-1084NPS / Jacob W. Frank

Day 5: 12.25 miles, 2,438 ft elevation gain

We had another early morning and took in the sunrise again. Achilles still swollen, we set out.

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We crossed back over the Snake River and made our way up Big Game Ridge as the clouds slowly started to build.

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This time our views at the top were obscured from a low cloud ceiling. We could see Yellowstone Lake but not the Teton Range. Just as we were finished eating lunch, we heard our first roll of thunder. We packed up and kept heading west.

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Just as we got off the ridge the rain started...and it didn't really stop until we made it back to the car the following day.

Day 6: 12.5 miles, 698 ft elevation gain

This day I only took one photo since it was raining all day. But as we made it back to Snake Hot Springs, it was too pretty to not take my camera out. The cold temps had caused the hot spring to steam.

20230904-jwf-119420230904-jwf-1194NPS / Jacob W. Frank

The last six miles of the trip was through a flooded trail and deep mud. We called it the "swamp of sorrow" and occasionally felt the need to yell "Artax!!!" After getting home and googling it, I realize that it's actually the "swamp of sadness." When we finally made it to the final crossing of the Snake, we didn't even bother changing shoes. We were covered in mud up to our knees, so we took the opportunity to use the crossing to wash all the mud off.

The trip was a lot of type-2 fun, but now that we are on the couch eating homemade muffins and looking at photos, we can look back on the tip and say it was a good time!


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John Boy Watkins(non-registered)
You da man! Happy you made it out of the jungle (concrete) and our able to have these adventures so often. I’m jealous doggie!
Sharon Frank(non-registered)
What a great adventure! The elevation chart looks cool. It would be great to see where you went on a map. Hope all your aches and pains are resolved.
Linda St Clair(non-registered)
Thank you for taking us along, through your blog, on an incredible journey. Like I said before, you two are beasts, in the very best sense, and a very special couple. Congratulations on planning and executing this exceptional hike.
Sarah E Baur aka Snuffygump on IG(non-registered)
All I can say is WOW! What a trek! What a major accomplishment! Great story and lovely documentation with photos
Thank you for this story… it has inspired me to look into a similar trek.
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