In general, swimming at Yellowstone is not advised. Thermal heated streams can boil. Mountain lakes and rivers can cause hypothermia. Currents may be too strong to swim safely. Nonetheless, although not widely advertised, there are one or two old fashion swimming holes in Yellowstone where swimming is permitted, although perhaps not encouraged. You just need to know where to look for them.

Firehole Waterfalls at Yellowstone
Our favorite is the Firehole Falls swimming area. It is located on the Firehole Canyon Drive, off the Grand Loop Road just south of Madison Junction. At a point where thermal heated water mixes with frigid mountain runoff the result is a nearly perfect spot to cool off on a warm afternoon.
Driving down the narrow one-way road (too narrow for RVs) you begin to wonder if you missed the swimming area. Never fear, you can’t miss it at the top of a steep cliff where you’ll see outhouses and a trail leading down to the swimming area.

Upstream of Firehole Falls the water calms enough for swimming
Upstream from this area are fast moving, dangerous rapids and down stream are the 40 foot Firehole Falls. In between, however, the current moves gently enough to allow body surfing but not so fast that you need to worry about getting washed away. Pools form around large rocks, providing areas to rest before you charge back upstream to enjoy the ride back down again.
Bring a towel and be advised that there are no life guards or Park officials nearby. Swimming is best in August when the days are warm and the water levels are lower than earlier in the summer. This was probably the most unexpected delight of our visit to Yellowstone — don’t miss it.
This is another in our series of Top 10 vacation activities for families visiting Yellowstone with teens and tweens.
We also swam at Firehole Falls this past summer and had a great time. Next time I will defintely bring a life jacket because I am not a very good swimmer and was a bit scared of the current.
I saw some folks swimming in Yellowstone when I was there. It looked like fun, but I don’t think I would do it!