Question On Filtering Water On The Yellowstone River

I friend of mine and I are launching on the Yellowstone River in Gardiner, Montana, in a few weeks and we will be paddling all the way to the confluence with the Missouri River in North Dakota. We have most of the logistics worked out, but still working on a few details.

Is anyone here familiar with the Yellowstone River past Billings, Montana, and do you think that it would be safe to filter the water from the river for drinking and cooking? Or, do you think that there is too much farm runoff along the river that it would be safe to drink the filtered water from the river for a few weeks?

For a little background, my friend and I are both experienced whitewater and sea kayakers. We’ve both also been on several paddling expeditions in length from 2 weeks to 5 months. The friend has done a source to sea of the Colorado River and I’ve paddled the lower Colorado River from the Grand Canyon to the Sea of Cortez 7 times over the last 10 years. The Yellowstone River will be our first time paddling a river on the eastern side of the continental divide.

In addition to the irrigated farmland, there are lots of cattle and feed lots between I-94 and the river from Billings to the ND line. I don’t know what may or may not be in the effluent from the refineries in Laurel and Billings.
I heard about one group of rafters (second hand) that used river water for cooking (but not drinking) after vigorous boiling and filtering.
Would not be my recommendation, though. I’d plan to pack drinking and cooking water.

Thanks. I don’t filter from the lower Colorado River for the same reasons.

Lots of cattle along the tributaries (Bighorn, Powder) too.

Yes Buffalo Alice is correct. Livestock are all around that area.
It’s very wise to filter that part of the river. And if the rains bring a fast thaw you’ll see the river is a bit cloudy with fine slit so that yet another reason to depend on filtration with your purification.
Our spring has been cool so far and the rivers are not full as of right now. Inside a week or two I expect to see the snows start to melt much faster, so all the rivers will likely be topped up pretty well. One thing that works well is to make a light frame that holds a piece of old blanket and a piece of bed sheet to make a pre-filter from. The sheet and blanket form a point that drops water into a pail and catches about 90% of the dirt. You then use a pumped filtration system to make drinking water from the pail. In doing that you can be out for a month and still have enough drinking and cooking water for your whole trip. It’s a system I have used in the past many times when guiding hunters in the back country. It’s wise to take extra filters with you, but by pre-filtering you can get a lot of time/gallons from 1 filter

Thanks and good advise.
Whenever I paddle desert rivers here in the southwest and canyon country there will be lots of silt in the rivers. I’ typically fill a 10 liter collapsible bucket and let the river water settle overnight. Then, use a bandanna and coffee filter as a pre-filter over the mouth of a pump filter. That’s also the way many groups filter water in the big ditch.

It’s hard to filter chemical contamination. I have used iodine and boiling as well as filtration. But some places just require bringing drinking water. For salt water I have seen where a pressure cooker and copper tubing are used to produce fresh water but that is time consuming.

Then there are survival solar stills Aquamate Solar Still Emergency Water Purification Inflatable Kit : Sports & Outdoors

Another form of solar freshwater collection is a clear plastic bag tied off over a branch full of leaves which collects the water being transpired by the plant. However, this isn’t practical for what you are planning. Although one could carry a lot of plastic bags to use at the same time to increase the amount of water. Toxic plants should be avoided.

Four foolproof ways to collect water in the wild - OAG (

If you are going to filter I would recommend a backcountry RO filter. that has a > 2 micron pore size which filters out 99.99% of viruses and bacteria. along with all heavy metals, but not chemical contaminants unless the molecule size is larger than 2 micron.

for that Id run through a RO filter first then through a filter system using activated carbon to remove chemical contamination.

So far I’ve never been in the situation when I’ve had to worry on chemical contamination, but that’s the way I’d proceed. (and maybe some old school water purification tablets just for good measure. )

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What a great trip. I have often thought of the same route but in a drift boat. You are right to consider the water quality downstream. The usual method to seek out side creeks and streams for water supply on big ag influenced rivers. Carry a decent sized bunch of containers. There are some towns along the way for re-supply. You can even buy ice and beer and find a restaurant here and there.

I would plan on using a quality water filter for times when you run out of water and have to drink from the river. Add some chlorine bleach a few drops per quart from a small bottle with a dropper.

There aren’t that many river trips I still want to do, but the Yellowstone is one of them.