Thousands of people from all over the world come to hike in the Wind River Range, and one of the most popular spots is the Cirque of the Towers. It’s a high alpine dreamland – towering mountains, meadows of wildflowers, granite rock and gurgling streams, all trickling down into a basin, which is home to Lonesome Lake.
But all those people visiting have to poop, which means that’s trickling down into Lonesome Lake, too. For years, it’s been an open secret that the seemingly pristine body of water isn’t so pristine. Now, new federal data suggest it’s actually 384 times higher in fecal matter than what’s considered safe.
WyoFile journalist Mike Koshmrl recently reported on this. He spoke to Wyoming Public Radio's Caitlin Tan.
Editor’s Note: This conversation has been lightly edited for clarity and brevity.
Caitlin Tan: The lake we’re talking about, Lonesome Lake in the Cirque, you and I have both spent time back there, and it's kind of been an open secret that this lake has problems. But then seeing this data was a little shocking to me.
Mike Koshmrl: Yeah, to me, the data on the fecal bacteria that the EPA sampled, it's called enterococci. It's totally jaw dropping, head turning, because of the setting, right? It's this amazing place along the Continental Divide with snow fields, 12,000-foot mountains and crystal clear water, in a setting where I think people would rightfully presume that it's safe and clean.
And yet, at the same time, it was the highest concentration of this fecal bacteria sampled anywhere in the country out of almost 1,000 samples the EPA took out of lakes, including urban areas and farm country. It turned out to be 384 times the concentration that the EPA would advise is safe for submersive recreational activity – in other words, like swimming – in that one sample back in August 2022. [It] was absolutely shocking.
Editor’s Note: The reading from Lonesome Lake was part of the EPA’s National Lakes Assessment, taken every five years. During the spring and summer of 2022, 80 field crews sampled 981 randomly chosen lakes, using standardized sampling procedures to collect data on biological, chemical, physical and recreational indicators.
CT: You said “one sample back in 2022.” It sounds like they're going to do some more sampling this summer. How worried should people be if they're planning to go to the Cirque this summer?
MK: The environmental regulators that I interviewed for my reporting, they didn't put a ton of weight into the number just because it was one sample. One sample is just like one snapshot in time.
But all that being said, it's been an open secret for a really long time. All you got to do is Google it, that Lonesome Lake is not a safe place to certainly get water from for drinking, even if you're filtering it. Swimming would be risky. If you accidentally ingest a little bit of water, it could make you sick, because there's just essentially the constituents of feces, likely human feces, given the amount of use there, that are making their way into the lake.
CT: And so for your story, you backpacked in there?
MK: Yeah. When I was talking to my editors, I said my first instinct is I want to go in there. We think the likely source of the problem is people pooping, right? It was a pretty weird reporting endeavor.
But I went and was like, ‘Hmm, if I had to poop right now, where would I go?’
So I went off the trail, dropping down to the lake. I'm in the Cirque and I looked for some tree stands. There's not that many trees when you're higher in the Cirque. So once you get down to the tree line, I'm sure a lot of people are like, ‘I want some privacy, and I didn't spend much time there at all.’
I didn't count the minutes, but I found at least – I stopped counting at seven, because it felt like a weird exercise – seven piles of shallow buried poop. At peak use in early to mid August, there's 400 people going through a week. What percentage of those people have to poop, and what percentage of them are burying it just a few inches under the soil? Then that whole basin gets socked in with snow, and it all melts. Even if you're abiding by the best practices and burying it, I think it's kind of unavoidable that a lot of the biomass you are leaving behind ends up ultimately in Lonesome Lake. And I think that's the problem.
CT: So everything's melting down into that lake, essentially,
MK: Yeah.
CT: When you hiked in, you saw people jumping in.
MK: Right at the outflow, where that river comes out of Lonesome Lake, there was a big group from Utah. In the process of chatting with them 12 miles into the backcountry, they air dropped me a video of one of the group doing a spectacular belly flop into the water of Lonesome Lake.
When he did it, he had no idea, which is why – in my opinion – this story is important. In an ideal scenario, there'd be signage or some way for people to know that this probably isn't a safe body of water to jump into. Currently, there's not. That guy, it's not like he was being reckless. He just had no idea.
CT: Going forward this summer, sounds like the best thing to do would be to not really be involved with that lake.
MK: Yeah, to err on the safe side. I threw a call to the great outdoor shop in Pinedale and just asked, ‘What do you tell people if they're going to Lonesome Lake?’ The gentleman who answered the phone said, ‘You know, I tell people absolutely do not drink out of Lonesome Lake. I tell people absolutely do not swim in Lonesome Lake.’
CT: On a broader scale, when we're thinking about more and more people are coming to visit the Winds. It's kind of ramping up over there. Do you think this is something that could become a larger problem in lakes in the Wind River Range?
MK: I would not personally jump into Island Lake. I would not jump into the most heavily used lakes in the Winds, based on what I've learned about the situation at Lonesome Lake, even if there's not data.
CT: What are possible solutions? There's some areas where I know people have to pack their poop out. But how enforceable would that even be if something like that happened for this area?
MK: Shoshone National Forest could require that. [They] could say if you poop in the Cirque of the Towers, you got to put it in a wag bag and you got to pack it out. But it does sound quite challenging to enforce.
A lot of the issue also just traces to high use. There is maybe a world that a lot of Wyoming residents don't want to imagine, where there are limits and permits to go to the most traveled portions of a place like the Winds. That exists where there's a lot more people in places like Colorado, and I think that Wyoming is really special, because we don't have that in a lot of places. But this situation points to maybe we need it sometimes, not just for the health of the landscape, but for our own health.
CT: We're still in the heat of summer. I'm sure people are planning backpacking trips. Any best practices pooping in the wilderness? Things to keep in mind?
MK: My understanding is to dig a hole as deep as you can possibly dig and cover it up and make it the earth you put on top as compact as possible
Editor’s Note: The National Park Service shares other tips for practicing Leave No Trace principles in the backcountry.
CT: And generally, trying to not be super close to bodies of water.
MK: Yeah, definitely.
CT: Mike, this is not the first time you have come on here to talk about lakes. WPR listeners might remember last fall you told us about a story you did on Little Soda Lake outside of Pinedale. It had turned red, a deep wine red, and it was a little unclear as to why. Do we have any updates on that?
MK: I did hear right when the ice came off the lake, the lake remained this striking, deep shade of red. But pretty quickly that abated.
Little Soda Lake became the first lake in the state of Wyoming in 2025 to have a cyanobacteria advisory, also known as blue green. Algae can be quite unsafe to ingest, so they are still kind of probing, is my understanding, to figure out what is the cause of the lake turning red.
But in the meantime, just like Lonesome Lake, don't go in Little Soda Lake, probably not the best idea at this time.
