Big Horn Canyon Reservoir in Wyoming

by  Hoodoo40

A self-supported trip created by Hoodoo40

Trip Overview

Big Horn Canyon National Recreation Area

Canoed on the Big Horn Canyon Reservoir. The Big Horn River is held back by Yellowtail Dam near Fort Smith, Montana (South of Hardin, MT). Below the dam, the Big Horn River is one of the busiest trout fishing streams.

Put in at OK-A-Ben Marina at the North end of the lake. Easy paddling, but need to keep an eye on the weather. Winds can be very bad and the North end of the lake is very wide. As this reservoir has steep cliffs all around, you may not see a storm moving in until it's on you. There are some picnic tables at the marina where there were marmots running around.

Most of the boating is motorboats (actually we were the only canoe). It is a huge reservoir, so we only saw others off and on. The Park Service has floating toilets here and there on the reservoir. Bring you own water to drink

We canoed from the marine and admired the steep canyon walls around us. The dam is over 500 feet tall, so the water is very deep at this end. Sheer walls at places, so you may go some distance before you can land. We explored various nooks as we headed South. As we meandered up river (or South), we had tail winds mostly. But as we turned corners, we often had head winds. The cliffs are various colors, the red ones at the top were the most colorful.

We headed up Black Canyon towards the campground. Of course we had a strong headwind with dark clouds above as we headed up this way. The campground has 17 sites and is first come first serve. We were there early enough and took a nice shaded one. We hung our hammocks and relaxed. It took us an easy 3 hours to get here, exploring on the way.

After a hot day, the evening cooled off nicely. Had an evening swim, water was cool but refreshing. The camp was filling up as this was the 4th of July week and folks were getting off work early. High 90's were predicted for the next day.

The next morning was nice and calm as we left camp early to beat the heat. We were able to stay in the shade at least half way to the take out. The first leg down the canyon was calm, but as we turned the corner, we had head winds. Not bad, and the wind was cool so it was nice.

Again, exploring here and there, we had an easy 2 hour paddle back to the marina.


Camping on the reservoir is limited. There is a boat in campground at Black Canyon (where we stayed) and another one at the South end of the reservoir. Camping is also allowed below the high water mark, very steep from what we saw. The reservoir was pretty full when we were there, so when lower the banks may be less steep.

There is various drive-in camping at the North end of the Reservoir. Around Fort Smith, they are located on the Afterbay (a smaller regulating reservoir below the big dam). There are some boat in camping on the other side of the Afterbay. There is some drive in and boat camping on the Southern end (near Lovell, WY).


Grumman 17-foot aluminum canoe with paddles


$5 entrance fee. Stop in the Fee Station coming into the Recreation area. The Federal Interagency Pass will also work ($80 in 2008).


From Billing, MT head East on Interstate 90 about 45 miles. Go South on Montana 313 (there are signs for Big Horn Canyon and Yellowtail Dam). Its another 55 miles to the Canyon.


We picked up a boat map at the Fee Station and they may also be available at the Visitor Center up by the dam. The boat map shows the camping, picnic areas and floating restrooms along the reservoir. There are day markers along the reservoir so you can see where you are.

Here is the PDF boating map website:
Here is the National Park Service website:

Trip Details

  • Trip Duration: 2-3 Day Trip
  • Sport/Activity: Kayaking, Canoeing
  • Skill Level: Beginner
  • Water Type: Flat/Sheltered Water

Trip Location