The East Fork of the Arkansas River originates on the north slope of Mount Arkansas as a trickling stream above timberline and percolates down a drainage of willows and wildflowers near the Climax mine on Fremont Pass. It will meander nearly 1,500 miles, through towns like Leadville, Cañon City, Fowler and Holly, and will be exploited in numerous ways before leaving Colorado and flowing into Kansas and on to the Mississippi River. (Mike Sweeney, Special to The Colorado Sun)
What is a river?
It depends on your point of view. Sun reporters have fanned out along the Arkansas River, from the headwaters near Leadville to the border with Kansas, to learn what the river means to people in the places it runs through.
ㅤ⚲ㅤ EAST FORK OF THE ARKANSAS HEADWATERS
It’s longer than the storied Colorado River. It rises and falls through more dramatic scenery and geology changes than any river in the state. Hosts 100 miles of gold medal trout waters. Delivers bounty to farmers and consumers. Supplies a lesser-known drinking water lifeline to Colorado’s biggest cities.
Yet nearly every inch of the Arkansas River through Colorado has been pummeled by humans for more than a century.
High up in a basin shouldering Mount Arkansas and Mount Democrat, a trickle of the East Fork of the Arkansas makes a gorgeous feint at being a majestic headwaters. The trickling fork dribbles through willows, Indian paintbrush and bear scat, but less than 2 miles after it’s begun, the Arkansas hits mine-waste rocks carefully sifted by massive landcrawlers and placed just-so by cranes, tumbles over an artificial waterfall, and disappears into a culvert under Colorado 91.
And that’s the easy part.
A few miles downstream, the Arkansas drains 150 years of mining waste in a still-active EPA Superfund cleanup 42 years after the toxic label was first slapped on Leadville. A local rancher and veterinarian finally got Colorado focused on a cleanup after his grazing cattle kept having stillbirths from drinking cadmium-laced river cocktails. A hundred miles of river suffocated native trout with leached heavy metals.
Just below Leadville, the volume of the Arkansas morphs into a conjoined twin of the Colorado River Basin. By nature, the Colorado sits across the Continental Divide, but through human intervention it sends much of its precious water under the Rockies and into pipes and buckets for delivery via the Arkansas River to homes and businesses in Aurora and Colorado Springs.
Miners overfished native trout until they disappeared, though wildlife officers still hope a lone survivor might surface someday on one of their regular electro-shock surveys of headwaters streams.
Downstream from Salida, the nature-wrapping artist Christo wanted to shade the Arkansas in a shiny linen awning. At Cañon City, the Arkansas becomes an amusement park showcasing the Royal Gorge, and then quickly a potential runoff catchment for a former uranium mill, and then urban wasteland working hard to get back to nature.
Pueblo Reservoir turns the mighty Ark into a sun-blasted boating playground for the Front Range. Exiting Pueblo to the Plains, the Arkansas gives life to farms while tantalizing far-away cities nurturing their growth visions. On the Plains, the streambed is so challenged by salts, radionuclides, fertilizers and low flows that agencies are building an entire second river in the form of a pipeline, bringing clean water from Pueblo Reservoir for 130 miles.
The Arkansas drains the biggest land mass of any of Colorado’s major river basins, but has the least volume of water. By the time the Arkansas leaves Colorado for Kansas near Holly, late summer heat and farm pumping turn it into a river of sand.
Is this any way to treat a river? Is the Arkansas an umbilical cord nursing all of Colorado’s living forms, or a paved-over conveyor for commerce?
“The Colorado River gets most of the attention in the state,” said Jerry Mallett, president of the nonprofit river defender Colorado Headwaters, but also a co-founder of Friends of Browns Canyon. In the 1980s and ’90s, Mallett said, the Upper Arkansas valley got attention for “those holding ponds that blew out and the river turned orange all the way down to Salida, killing everything in it.”
But there are hard-won signs of a physical revival for the Arkansas. And appreciation for what it once was and could be again. If humans ruined the natural Upper and Lower Ark in Colorado, they also believe they are the ones to bring it back. It’s the paradox of engineering nature to get back to nature.
In 1992, clients of Greg Felt’s guide shop never caught a brown trout older than two years or bigger than 10 inches. Now they regularly hook 9-year-old fighters measuring 20 inches.
Front Range cities that locked up much of the Arkansas flow have agreed to keep more water in the river when rafting companies want to float, and take more water out of the river when trout and caddis flies need to reproduce in shallows.
Cañon City is rinsing a prison-town profile with 50 miles of recreation trails around its Arkansas River heart, and planning to turn the most industrial, concrete-shellacked section of the river into a shopper-tainment walk.
In perhaps the hardest struggle to bend the Arkansas back to its Colorado heritage, Lower Arkansas farm communities are organizing to fight off urban drinking water grabs and revive what it means to be a birthing ground for both produce and people.
Will Clements is a professor of river biology and toxicology at Colorado State University, and has helped lead decades of water quality studies on the Arkansas as the mining waste was cleaned up. When the EPA started California Gulch Superfund work in and around Leadville, despite intense skepticism from many government-leery residents, heavy metals in the Arkansas were 10 times or more the levels that would kill all organic life, Clement said.
In 2025, Clements said, “It’s by no means a pristine system, but it certainly has recovered. Pretty dramatically.”
Rehabbing the rebuilt Arkansas
The Climax molybdenum mine north of Leadville closed the modern era of goading the Arkansas with an engineered burial.
In the big bend of Colorado 91 south of Fremont Pass, where the road makes a gooseneck turn over the trickling East Fork of the Arkansas, the Storke Yard mineshaft headframe still marks the entrance to what used to be one of the world’s largest underground mines. Before Climax switched to the open-air tearing of molybdenum ore off Bartlett Mountain, debris came out the Storke Yards shaft and filled up the valley.
In 1980, Climax made formal the interment of the East Fork, channeling what was left of the creek water in a 7-foot diameter pipeline under tons of boulder-size waste, for 2,000 feet. Three years later and 16 miles downstream, Doc Smith would launch the Superfund cleanup of the Arkansas with true tales of dying cattle.
By 2007, the Superfund cleanup at Leadville was well underway, and Climax decided to scour the Arkansas side of its Continental Divide-straddling moly mine. The company, now owned by multinational Freeport McMoRan, commissioned hydrologists to disinter the East Fork, sift and place boulders to recreate a fish-friendly river channel, pump concrete to hold the rocks together, and add a short waterfall to delight passing tourists.
It’s by no means a pristine system, but it certainly has recovered. Pretty dramatically.
— Will Clements, Professor of river biology and toxicology at Colorado State University
And it worked. Instead of seeing the life-giving runoff of Mount Arkansas and Mount Democrat extinguished so soon after starting its cross-country run to the Mississippi, the high East Fork is now home to workaholic beavers, thriving willow thickets and ponds where trout are beginning to reproduce naturally.
“You can see a legacy of some of the land use as you look at aerial imagery up there,” said Eric Richer, a stream restoration scientist with Colorado Parks and Wildlife. “In some places, where willows are all over the place, it’s probably closer to the historical condition.”
The beavers have become so industrious at the highway culvert and the ponds below that wildlife officers have cleared some of the toothsome structures away to promote fish-friendly stream flow. The wildlife agency in early August did its usual fish counts on the stretch from Storke Yards, through a dozen miles of stream toward Leadville, and on to the confluence with Twin Lakes Reservoir, using electrified barges that temporarily shock fish to the surface for a census.
“The numbers actually look really good. Everything looked actually better than in years previous,” said Alex Townsend, an aquatic biologist for Colorado Parks and Wildlife in the Upper Arkansas region. “The riparian area through that area, it looks very healthy.”
There’s only so much humans can do, though, to reverse-engineer the river back to a future of natural health. Before Leadville became a mining and smelting hub in the 1870s, the uppermost reaches of the Arkansas featured one of six native Colorado cutthroat trout subspecies, the yellowfin cutthroat, lurking in stream eddies at up to 10 pounds. Foraging mining families caught up most of the yellowfins, and the remainder lost out to rainbow trout introduced from the Pacific Northwest in part to keep the miners fed, now the dominant game fish in Colorado.
“Evidence suggests the yellowfin is now extinct,” Richer said. “Unless Alex found one this summer.”
Alas, Alex did not.
Viewed from above, Tennessee Creek (bottom of the screen) and the East Fork of the Arkansas River meet to begin the long flow across Colorado, Kansas, Oklahoma and Arkansas to the Mississippi River . (Mike Sweeney, Special to The Colorado Sun)
Reversing a century of river abuse
Just west of Leadville, the Arkansas picks up in volume with the addition of Tennessee Creek, the Homestake project’s Colorado River water through Turquoise Lake, and California Gulch. But until the 1990s Superfund cleanup got underway, what came in through the gulch was decidedly unwelcome.
The legendary gold and silver mines in the hills to the east of Leadville unearthed rock laced with toxic heavy metals like cadmium, copper, zinc and arsenic. Poking mine shafts into the hills was like drilling a hole through a toxic sponge, and snowmelt annually flushes heavy metals through the mines and down into any nearby streambed like California Gulch. On its way downstream, the runoff also leaches more metals out of the ore and smelter slag piles flanking U.S. 24 on its way out of Leadville.
Old photos of the gulch meeting the Arkansas mainstem look like someone poured bilge water into a swimming pool. In California Gulch, the contamination was so bad that it killed not just the fish but all the vegetation that helped hold the banks in place, leaving the channel an eroded wasteland of toxic sand and bruising rocks.
After listing Leadville for the Superfund in 1983, the EPA’s most effective treatments were a water filtration plant for Yak Tunnel runoff, and holding ponds for the minerals leached by snowmelt running through spent ore and smelter slag all around town.
But Lake County residents were not always fans of the cleanup, which stretched on for decades and threatened to remove ore piles that locals considered historic features rather than toxic bugs of life in the high country. The EPA’s reach extended to soil removal around Leadville homes that federal officials worried could raise lead levels in children’s brains, offending residents who thought their kids were just fine.
Farther south in Chaffee County, though, the cleanup prompts little celebrations every time knowledgeable anglers snap a fly rod.
“The water quality work that went on in the ‘90s up in Lake County, truly, truly impacted the biology of the Arkansas River in a tremendous way,” said Felt, the angling outfitter and Upper Arkansas Water Conservancy District commissioner.
In the late ’80s and early ’90s, Felt said, expert anglers had to settle for bizarrely skinny trout, never aging more than two or three years or growing past a few inches, with a 10-inch fish counting as a prize. The absence of caddisfly swarms was like a shuttered dancehall.
And then the toxic silt receded up California Gulch.
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“Certainly by 2002 we saw, just, wow. The fish were getting bigger, they were healthier, they were clearly living longer,” Felt said. Partly through state revegetation, the bank-holding plants came back, and with them, the flies.
“Fast forward even into the early aughts of the 2000s, and we’re seeing fish live 7, 8, 9 years and growing. We catch fish every year over 20 inches,” Felt said.
Before 2013, as the fishery undeniably improved and the Upper Arkansas economy largely turned away from mining toward the rafting, fishing and hiking business, an argument began that was laced with competing ironies. Many outdoors leaders wanted the Arkansas from Leadville to the Royal Gorge designated official gold medal trout stream, meaning a reliable number of brag-worthy fish poundage could be found in every acre.
Others worried the designation would bring too many international fly-fishers wanting to bag all the gold medal streams, and put too much pressure on the trout population. It may have been the 20-year striving of Bulgarian-born fabric artist Christo to drape 6 miles of the river that helped persuade Upper Arkansas residents to more passionately embrace their humble stream.
“In the wake of the Christo art proposal, some of us felt that an additional layer of protection for the fishery could maybe forestall some future stuff like that, or at least provide for a little more reflection,” Felt said. Colorado declared the Arkansas gold medal stretch official in 2014 — Christo shredded his oft-reviled idea in 2017.
“It’s kind of an amazing turnaround, in about 18 years, let’s say, going from truly a third-rate fishery that people drove right past on their way to the Rio Grande, or Gunnison, to the longest stretch of gold medal waters in the state,” Felt said.
There’s more river health education to be done, but not in a direction anyone expected.
There are so many healthy brown trout in some of the gold medal stretches that Colorado wildlife officials want anglers to suspend their gradually acquired ethical stance that catch-and-release is the only way to fish. After creel surveys showed successful anglers were putting everything back into the water instead of keeping trophies, the state loosened bag limits in popular areas above Leadville and near Browns Canyon. It would actually be healthier for the brown trout population if anglers kept more 12 to 14 inch fish and cleared life space for monster browns.
“People can take what they want out of the river right now, and it’s not going to really hurt the numbers,” Townsend said. “It’s kind of an interesting angler change.”
A new threat or a new start?
Is the past ever past? Not in a mining town.
Just as Lake County residents were getting comfortable with scrubbed-clean, mountain-fed streams threading their way past historic ore piles, a new way of reworking the Upper Arkansas and its tributaries threatened the angle of repose.
CJK Milling now wants to push around and pick apart 140,000 tons of those scattered ore piles, in search of the gold that resides in microscopic but lucrative amounts inside the rocks. The milling partners want to expand a state permit to process a small amount of ore into a major operation. It was first pitched as a cyanide-soaked industrial milling, and later modified to an environmentally friendly but vaguely defined “chemistry” process licensed from an outside company.
The partners say they would be doing Lake County a favor by “un-scarring” the land. A residents group has responded with a 100-page environmental analysis and is shouting leave-the-piles-alone at every regulatory body.
Volunteers with the group are steeped in not just the CJK Milling applications with the state reclamation board, but also with the voluminous periodic Superfund updates from the EPA. They are adamant that they do not oppose industrial development for Leadville, just the kind of vague, potentially reckless mineral extraction that could restart the toxic drips into the Arkansas.
I would like to see the Arkansas River become a gold medal river from start to finish in Colorado.
— Ruth Goltzer, volunteer and resident of Leadville
“It’s not just our community,” said Ruth Goltzer, who lives half the year in Leadville. “It’s all the way down the Arkansas. Last year, there were just shy of 700 objections submitted to the (mine reclamation board), and that was not just from people who some would say are crazy. Rafting companies and fishing guides and people who make their living off the river, OK, and a wide variety of the businesses, and many, many, many individuals.”
The group fully recognizes how mining built Leadville, and how hundreds of county residents rely on good-paying jobs at the Climax moly mine straddling Lake and Summit Counties.
“We always want to be respectful, but we are protective,” Goltzer said.
“I would like to see the Arkansas River become a gold medal river from start to finish in Colorado. And I know that there’s a lot of work that needs to be done all along the way. But, you know, it’s up to us,” she said. “It’s up to us these days to be protective. What’s going to happen to things like the Clean Water Act? Right?”