Mill Creek beaver dams wiped out

Sara Melnicoff sees constant threats to Mill Creek Canyon’s fragile desert and riparian ecosystems, from intentionally set fires to growing numbers of visitors who trample cryptobiotic soils and vegetation along the trail to a popular recreational area.

Perhaps no sight has been more distressing, though, than the one that the Mill Creek Partnership leader saw last month: the remnants of 11 beaver dams at various points below the creek’s left- and right-hand forks that were wiped out after an incident of suspected vandalism.

Up until that point, Melnicoff had been feeling upbeat about the signs of beaver recovery along the much-loved – and often-abused – waterway.

“It just gave me so much joy, and then – boom,” Melnicoff said.

The suspected vandalism is believed to have occurred in mid-July, when a federal employee who is new to the area reported that she spotted a man who was standing in the middle of the stream, removing wood from the dams by hand.

Powerhouse Lane resident Brian Murdock, who works for the U.S. Forest Service, said the employee told him that she assumed the man worked for another federal agency, so she didn’t think any more of the sight.

But when Murdock went for a hike up the canyon on Sunday, July 16, it was clear to him that something was wrong: Four or five of the biggest beaver dams that are visible from the main trail through the canyon showed obvious signs of vandalism, he said.

“(Someone) had gone and ripped all of the wood out,” Murdock said. “It was a notch, basically.”

Just over one week later, floodwaters from heavy monsoonal rains swept through the canyon, wiping out the damaged remains of all 11 dams – some of which were less visible from the trail. And while Murdock said it’s conceivable that the floodwaters could have destroyed the dams in any event, he’s certain that the initial damage was not a natural phenomenon.

“It was obviously human-caused vandalism,” Murdock said. “A flood would have probably ripped them out, but (the signs of damage were) just a straight line through the dams.”

Melnicoff said she has photographic evidence of the suspicious person who was standing in the middle of the creek, which she’s forwarded on to the Utah Division of Wildlife Resources (DWR). The division’s investigation into the report is ongoing, according to DWR Conservation Officer Adam Wallerstein, who had no further comment on the issue.

The U.S. Bureau of Land Management (BLM) administers lands within the canyon. But since the DWR has jurisdiction over wildlife in Utah, BLM Moab Field Manager Christina Price is encouraging anyone else who may have seen anything unusual to report the incident to that agency.

“BLM appreciates individuals coming forward to report incidents of suspected vandalism,” Price said. “In this case, since wildlife is involved, we reached out to the Utah Division of Wildlife Resources and BLM will continue to coordinate with them as they look into the reported incidents.”

Mill Creek Partnership volunteer Mary O’Brien said it was obvious that something was amiss the first time she approached the old Powerhouse Dam after the damage and noticed brown water spilling over it.

“I thought, ‘We’re in trouble here,’ because the water is usually clear unless it’s after a storm,” she said.

O’Brien, who also works as a staff scientist and Utah forests program director with Grand Canyon Trust, said the Mill Creek Canyon beaver population likely included members of one family.

The species are migratory, so if they didn’t die in the floods, O’Brien said they’re somewhere in the area – perhaps the Colorado River.

“Beavers do come and go, particularly in the Southwest,” she said.

O’Brien said that beaver have occupied Mill Creek on and off for years, although they’d never developed a system like the one that existed until last month – at least not in the time that she’s lived in Grand County.

“This was the first time in 14 years that I’d seen such a complete set (of dams),” she said.

Mill Creek Partnership sees growing signs of visitor abuse

Melnicoff has been patrolling the canyon just about every day since 2003, cleaning up after human visitors and their dogs, greeting visitors and working to raise environmental awareness about the area and its unique ecosystems.

Fourteen or so years later, Melnicoff still never tires of her surroundings: Every time that she walks up and down the main trail – or ventures off on a side path – she’ll see something new.

“It’s never the same place,” she said. “The light’s different; the water levels are different; the plants are different.”

But visitor use patterns have also changed – increasing year after year – and Melnicoff said the place that she loves so much is under “constant assault.”

The spring visitor season, in particular, is the worst time of year in terms of impacts to the canyon, she said: Even local residents who once flocked there to party now shy away from it.

“It’s weird,” she said. “It’s shifted from intentional partying and leaving trash behind to tourists not knowing where the trail is and trampling everything. But it’s always a matter of (visitor) numbers.”

The BLM does not actively promote visitation to the area, but with the advent and rise of the Internet, word of the canyon and its beauty got out.

In many cases, Melnicoff said, visitors are unfamiliar with their surroundings, and they don’t take care to watch where they step.

“People just don’t realize, especially a lot of visitors who come, what a fragile desert ecosystem this is, and the impact of their feet (on the soils),” she said.

In spite of the growing visitor numbers, the beavers appeared to be thriving in the creek, expanding their network of dams until last month.

“I had been pleased that there were so many people who came up Mill Creek every day, and no one was bothering any of the dams,” Melnicoff said.

Tens of millions of beaver once occupied streams and other riparian areas across the vast region, but trappers decimated their numbers in the 19th Century. The species’ population across North America has since rebounded to an estimated 10 to 15 million individuals.

Beaver tend to be shy around humans, and while they were a rare sight even when they were swimming around their dams in Mill Creek, their absence is weighing on regular visitors like Melnicoff and O’Brien.

“The creek is feeling a little lonelier for not having the beaver in it,” O’Brien said. “It’s like you had a partner in Mill Creek, and that partnership is gone for now – but not forever.”

If there’s an upside, it may be that land managers and wildlife officials can use the incident as a teaching tool to educate the public about a species that enhances one of the West’s most precious resources: riparian areas.

They build their dams because they need at least 2.5 feet of water to access food without having to wander around on land. In doing so, they expand riparian areas by piling up sediment behind their dams, O’Brien said, which raises the floors of the streams.

“When the water system is up, then it’s raising that water table and it’s accessible farther out,” O’Brien said.

The widened streams and riparian areas they foster attract all kinds of wildlife, from water voles, river otters and mink to fish and cavity-nesting birds.

“There’s a whole complex of species that comes with beaver,” O’Brien said.

The dams also slow the effects of streambank erosion from gouging.

“In the absence of these dams, the water just shoots down,” she said. “It has some meanders, but it’s a more gouging force.”

Melnicoff said the dams were crucial in slowing and containing floodwaters that rush down toward Moab from the creek’s upper watershed.

“When they were this close together, that’s when they really start acting like speedbumps,” Melnicoff said.

Now that they appear to have vanished from the creek, O’Brien said it’s unlikely that the beavers will rebuild their dams anytime soon.

“It could be years before we see a dam or two here again,” she said.

But she is confident that they’ll eventually return.

“They’ve still got vegetation here,” she said.

Melnicoff said that visitors who have complaints or concerns about other issues in the canyon, such as poison ivy along the trails, should contact her – or land managers – instead of taking matters into their own hands.

“If anyone has a complaint about an issue, definitely call the partnership of the BLM, and we’ll try to address it right away,” she said.

Advocates seek leads on suspected vandal

The creek is feeling a little lonelier for not having the beaver in it.

If you have any information about the destruction of the beaver dams, contact the DWR’s Southeastern Region Office at 435-613-3700. For more information about other issues in the canyon, contact Sara Melnicoff at 435-401-4685, or the BLM at 435-259-2100.