Three Island Crossing State Park: history, Oregon Trail, views

Three Island Crossing State Park: history, Oregon Trail, views

Three defining characteristics of southern Idaho are sagebrush, the Snake River and the Oregon Trail. These things combine near Glenns Ferry, Idaho, at Three Island Crossing State Park.

Imagine you were a pioneer headed to Oregon. You’ve made it past the Great Plains and the Rocky Mountains and are on the home stretch. One of the most perilous obstacles you have left is crossing the Snake River. The Snake River gets its name because, just like a snake, it winds and coils its way across the land. The Oregon Trail pioneers would have come in contact with it several times on their journey, but at Three Island State Park, they had the choice of crossing it.

Three Island Crossing State Park entrance sign
Three Island State Park entrance.

The Three Island State Park tells the story of these pioneers in a park setting. You can learn about history while you camp and play frisbee golf right next to the large river. 

State Park Overview

Rating: 4 out of 5.

Overall, we give this state park four stars.

This place is teeming with history. It gets three stars just because of that. The visitor center is also nice. Not all of Idaho’s state parks have visitor centers, let alone good ones like the one at Three Island.

Snake River Three Island Crossing State Park visitors center
The visitors center at Three Island Crossing State Park.


  • History galore
  • Pretty scenery
  • Close to Boise
  • Nice visitor center


  • Don’t do actual reenactments anymore
  • Snakes (real one, not the river)
  • Hot and dry
Water snake at Three Island Crossing State Park.
Keep your eyes peeled for snakes.

What To Do

The main thing to do at Three Island Crossing State Park is to learn the history of area. The visitor center has a few explanations to help you understand how the pioneers crossed. There is a replica wagon to help you get into the mood of things and an old ferry carcass that you can climb on and around. 

For non-history related activities, there is a campground and a frisbee golf course. 

Exploring Three Island Crossing State Park.


  • Campsites
  • Showers/bathrooms

For all of the specifics, check out the parks and rec’s website for Three Island Crossing State Park.

The Crowd Situation

Rating: 4 out of 5.

There were only a handful of other visitors. Good thing because only five visitors were allowed at a time in the visitor center. We didn’t have to wait. 

Visitors center at Three Island Crossing State Park.
Inside the visitors center.

Unique to Three Island Crossing State Park

This park was unique because you could see the path etched into the cliff line where the wagons would come down to the Snake River. Other than by Hagerman National Monument, this is the clearest spot we’ve seen of wagon trails. 

A Little History about Three Island Crossing State Park

Three Island State Park is a state park due to its history. When the pioneers arrived here, they had a choice of making the crossing and taking the easier northern route to Oregon. If they were unable to cross or decided it was too dangerous, they would have to take the more challenging southern route. 

This area is called Three Island because there are (wait for it….) three islands in the middle of the Snake. They would use this land mass to hopscotch their way across the river, so they didn’t have to cross it all through the water. The river is pretty wide at this point, so it made sense to try to go use the islands as shortcuts. 

old wagons at Three Island Crossing State Park
Can you imagine trying to cross a river in one of these bad boys?

When I said the crossing was dangerous, I wasn’t kidding. Lots of people and animals were swept away in the current. In the visitor center we learned the story of one woman who did successfully make it across the river on the back of a horse. The women were placed on the horses and the men tried to make sure the oxen didn’t drown or get swept downstream. The water level was deep enough that even on the horse the woman was mostly underwater. 

Three Island became a state park in 1971. Up until a few years ago, history buffs (and probably locals looking for a good time) used to do reenactments of the crossing every summer. It is one of my regrets that as a Boisean and just down the freeway from this park, I never made it out to the park while they were still doing this. 

old Snake River Ferryboat
Life got easier for the would-be crossers when industrious individuals created river crossing ferry boats.

Explore Nearby

Our experience(s) at Three Island Crossing State Park

We arrived at the park and I was confused at how nice the visitor center was. Once we went inside I realized this park must partner with the National Park System, thus the feds must have ponied up and paid for some of the building.

We walked through the visitor center and learned the history of the area. From the vantage point of the visitor center on the hill, you can see across the river to the wagon trails. You can also see the islands that give this park its name. 

Here’s a highly scientific and educated explanation of the crossing.

The Oregon Trail at Three Island Crossing State Park

We went outside and took a well-marked trail down to the river. We were officially on the Oregon Trail at this point, or so the markers told us. If I closed my eyes and imagined myself here 150 years ago…I realized I would have made a horrible pioneer and all wagon trains were lucky I wasn’t a part of them. This area is very dry and we were there on a hot summer’s day. To have been walking for the last few months…yuck. Just yuck. 

Oregon Trail marker sign at Three Island Crossing State Park
On the Oregon Trail!

At the river we had an unfortunate encounter with a water snake. After seeing that I was ready to head back up to check out the old ferry (which was put in place so the pioneers didn’t have to cross the river on foot) and a replica wagon. The wagon was fun to see; people had built this and then got on the trail on the centennial anniversary of the Oregon Trail. 


If you are into history, we highly recommend Three Island State Park. You can appreciate how difficult it would have been to have crossed this country on the Oregon Trail. If you are not into history, you can enjoy the sage brush and the Snake.

We visited Three Island State Park as part of our Idaho State Parks Challenge. The challenge consists of visiting all of Idaho’s state parks in one year. We made up this challenge to see a bit more of our beautiful state and help alleviate the restlessness caused by Covid-19 travel restrictions. Feel free to join the challenge!

Related posts you might like:

Or if you want to see all of our posts, visit Past Posts.

1 thought on “Three Island Crossing State Park: history, Oregon Trail, views”

Leave a Reply

Your email address will not be published. Required fields are marked *