Amid the heat of mid-July in Colorado Springs, about a dozen rainbow trout floated in a pond outside Angler’s Covey, lifeless.

“We just couldn’t keep our pond cool enough, even with trying to keep water flowing in there,” said the fly shop’s longtime owner, David Leinweber.

It was a troubling sign of the times across Colorado, where temperatures have lingered high and rivers and creeks have dropped low, making them more susceptible to trout-killing heat.

Later in July, on the lower reaches of the Elk River, Colorado Parks and Wildlife reported a more disturbing sight: about 300 dead mountain whitefish “where the water temperature likely exceeded 80 degrees,” according to a news release advising anglers to avoid the waterway near Steamboat Springs.

Along with heat, fishing adds more stress to cold-water species. Hence an unusual wave of voluntary closures CPW enacted throughout July.

The month ended with a broad call for anglers “to adjust practices” across the state’s 6,000-plus miles of fishing streams. 

“Water temperatures in excess of 70 degrees increase mortality rate for catch-and-release trout significantly,” CPW cautioned. “Late-afternoon readings on the Rio Grande, Arkansas and Colorado Rivers and some of their tributaries are regularly exceeding 70 degrees, with conditions expected to worsen.”

Also at the end of July, CPW called on anglers to avoid fishing on go-to parts of the South Platte River and Clear Creek from noon through midnight. This included the South Platte’s Dream Stream and Clear Creek’s similarly popular stretch from Vanover Park in Golden to the Tunnel 1 Trailhead. Those stretches and others reportedly hovered below 50% of flows typically expected for the time of year. 

Elsewhere in July, CPW was measuring flows below 20% of historical averages. And around the same time, the agency reported an “extremely rare” observation on popular stretches of the Colorado and Fraser rivers: Even at night, water temperatures exceeded 60 degrees. The state’s trout are known to thrive in temperatures between 45 and 60 degrees.

The voluntary afternoon closures on those fisheries grew CPW’s list past 20 around the state. The closures amounted to more than 450 miles of streams, said Josh Nehring, deputy assistant director of CPW’s aquatic branch.

“A pretty extensive list for sure,” he said. “Certainly in my career with CPW, which is about 16 years now, I haven’t seen quite this many.” 

But the closures aren’t exactly surprising, he said. Following a historically dry and warm winter and spring, CPW feared fisheries running low without snowmelt. Fears were compounded with the hot, dry start to summer. 

“It’s just like when we have a really bad, smoky day because of fires. We have a difficult time breathing,” Leinweber said. With trout, “when the water is warmer, there’s less oxygen in the water.” 

Water heats faster when it’s lower ー like boiling a cup compared with a gallon, Leinweber said. And so he understood the voluntary closures on busy parts of the South Platte close to home. 

“It’s harder for (fish) to recover, and they can die if they’re handled too long,” he said.

That explains why CPW considers fishing pressure and popularity when enacting closures. 

“Even if they’re not biting, anglers wading in the water and moving around the stream could displace the fish and further stress them,” Nehring said. 

He was quick to point out thousands of miles of rivers and creeks in the state under no closures. Additionally, CPW counts more than 1,300 lakes and reservoirs for fishing. 

“There’s a lot of other angling opportunities,” Nehring said. “We just ask that people pack a thermometer with them and once (water) temperatures get up to 71 degrees, try to look to higher-elevation streams or lakes.” 

Fish ideally do the same to survive ー swim higher to cooler waters. CPW aquatic biologist Eric Gardunio said he expected they would in a news release announcing a voluntary afternoon closure on “one of the premier trout fisheries in Colorado:” a 12-mile stretch from the North Fork of the Gunnison.

“This section is an important asset to the local community, and we understand that the current drought is limiting angling options and outfitter opportunities,” Gardunio said. “This voluntary closure is a great chance for the anglers and recreators who value this river to give it a break and allow it to recover. It is a resilient fishery, and I am sure with some help it will be back to its normal quality once the water conditions improve.”

This is the hope of Steamboat Springs anglers who have been asked to avoid the Yampa River through town. 

“In my life, I’ve never seen it get quite this low,” said Colton Creamer, who grew up in town and manages Steamboat Flyfisher. 

In the meantime, the shop’s guides have been taking clients up into Flat Tops Wilderness. 

“It’s definitely tougher to slip out for a quick couple of hours because all the stuff right close to town is closed,” Creamer said. But the trips “have been a lot of fun,” he added. “It’s been a lot of fun for guides, too, guiding stuff we don’t usually do.” 

In the opposite southwest part of the state, guides around the San Juan and Animas rivers have similarly ventured to the high country. At Duranglers Flies and Supplies, Andy McKinley sounded grateful for closures on parts of those rivers. 

“Saves our fish,” he said. 

That’s the hope, anyway. 

Fish were indeed “resilient,” Nehring said, adding recent monsoonal rains can help. 

“But sometimes it can be good and bad,” he said. “With it being so dry and the streams being so low, the soils are so dry that a lot of that water will just run right off and not soak into the soil.”

Ensuing flash flooding “could potentially affect fisheries,” he said. Ash and debris from this summer’s large wildfires are another concern.

“We could have localized effects on populations. We just don’t know the extent of it right now,” Nehring said. 

Anglers can help by keeping hooked fish in the water, he said. “Avoid doing the selfie you want, even if it’s a real nice fish. Maybe take a picture of them in the water.”

And while one might seek higher elevations for cooler streams and lakes, “we also have a lot of warm-water fishing opportunities as well,” Nehring said. The interactive Colorado Fishing Atlas maps several fisheries on the plains for walleye, bass, catfish and more. 

The atlas tracks conditions, too ー boating closures or limits due to low water at Barr Lake, Boyd Lake and John Martin Reservoir, for example. On the southeast plains, Two Buttes Reservoir was found completely dry before the summer. 

But it’s not all “doom and gloom,” Becky Leinweber emphasized. While representing the owning family of Angler’s Covey, she has led Pikes Peak Outdoor Recreation Alliance, a regional collaboration promoting industry and tourism. 

“You can still have amazing experiences out there,” Leinweber said. “It might just be a little bit different. You might just have to plan ahead a little bit more.”