What’s the best time to float the Salmon River? It’s a question I’ve often heard and attempted to answer. Mostly it comes towards the end of a day of rafting. People are already thinking of the next time they will get to go and start wondering “when should I plan it?”. I suspect most people want me to throw a date out at them - June 5th! - but as someone who gets to enjoy all the different faces the river has to offer; I feel obligated to try to represent each one and what they have to offer and let them decide (because I can’t).
At 425 miles the Salmon is one of the longest free flowing rivers in the U.S. (meaning there are no damns). This is significant because unlike a damned river whose flow is controlled by the output at the damn, the Salmon’s water level is reactive depending on the conditions of its drainage. Once water starts to flow in the Salmon Drainage it just keeps on moving.
The greatest contributor to water around here in Idaho is snow and thanks to our mountains that snow stays frozen longer the higher up it is. A typical year brings snow in the winter where it stays put until temperatures warm up. Then it melts and flows downhill feeding the river. This will happen over a long period of time, but the window in which the most snow melts, the fastest, is called high water. Highwater usually happens right around the beginning of June, but this can vary either way by a month. After high water the river will slowly lower as the remaining snow melts until you’re left with just springs feeding the river, resulting in our low water level. During all this there can be some rainstorms that will bump the river up, but you can see the trend. Fall usually brings serious enough storms mixed with warm days to bring water levels back up a bit until it gets cold enough that the snow starts to stay put again forming next year’s snowpack.
Now for the part you came to hear, let’s talk about what the rafting experience is depending on water level. Remember these are generalities and nature doesn’t use days of the month. We’ll split it up into four categories. Pre-highwater, highwater, post-highwater, and low water.
Pre-highwater is when snow down low is and has melted, from when the river is free of ice to highwater. This is a great to fish or go on a scenic float where you won’t get wet. Many animals like elk or deer are still around and haven’t headed for the high country yet. The weather can still be cold but mixed with beautiful sunny days as well. However, the water temperature is still downright frigid. Pre-highwater is generally March to the end of May.
"Highwater" - The word has a ring to it, and to any boater, it brings a twinge of excitement. Highwater brings big waves, fast water, and a whole new river. It’s funny how a place in the river that isn’t even a rapid in low water can be a serious challenge at this time, or just the opposite. This is for those looking for the most excitement and challenge. With big water comes big fun, but you must be willing to be tough too. Although the weather has warmed up the water temperature is still cold and big splashes are the name of the game. It’s a good idea to wear a wetsuit and even a rain jacket when rafting through highwater. Highwater often happens sometime between the end of May to middle of June.
Post-highwater is when summer has arrived. Water levels will trend towards a decline from here to the fall. With lowering water levels comes a rise in water temperatures, making swimming more enjoyable. Rapids are a blast with a mixture of dodging rocks and powering through waves. Post-highwater is around mid-June to the beginning of August.
Low water is my favorite time of year for multi-day trips. Hot days and warm water make swimming the greatest of pastimes. Go all day and night without needing anything more than a t-shirt and swimming suit. Slow down with the river and have a chance to really take it all in. Low water also brings new challenges to running rapids. Squeezing through tight spots in-between rocks requires the next level of teamwork from a paddle boat crew. Low water can be from mid-August to mid-September.
I couldn’t pick the best time to go rafting on the Salmon River. There are parts about each phase of the summer I love, the best thing to me is seeing how the river changes and getting to know each phase. My advice is to go as often, and at varied times, as you can!