Study: Human-caused fires in San Juan forest often occur near roads, trails

Campfire smoke lingers inside the San Juan National Forest at a designated campsite on July 4, 2021, near Lake City. (Hugh Carey, The Colorado Sun)
A study of fires in the San Juan National Forest showed that people don’t start the majority of Southwest Colorado’s wildfires, but those they do ignite are near roads and hiking trails

In July 2020, Seth Zachek was volunteering at a wildly popular trail in the San Juan mountains just outside of Silverton. The goal: teaching hikers how to tread lightly in the Ice Lakes Basin, a pristine wonderland high in the range.

The irony wasn’t lost on Zachek when volunteers discovered a plume of smoke and an unsafe, illegal campfire close to the trailhead.

“Some guy had dragged a whole half of a tree into this campfire,” Zachek said. “And it was, like, 8-foot-high flames next to the trailhead with all these people around.”

His trepidation turned out to be warranted. Three months later, a wildfire likely sparked by a cigarette butt burned through the lower basin, forcing a helicopter evacuation of 28 people and closing the trail for almost a year.

It was a scenario that advocates were trying to prevent, and one scrutinized in research published last month in the journal Natural Hazards.

Humans started more than a quarter of all wildfires from 2000 to 2018 in San Juan National Forest, and those fires tended to be closer to campgrounds, trails and roads, clear evidence that people enjoying the outdoors are often to blame, wrote University of North Alabama researchers who reviewed 18 years of data from the southern Colorado forest.

The 2020 Ice Fire started at a boulder about 75 feet from the Ice Lakes Trail. The fire was likely human-caused. (Courtesy of U.S. Forest Service)

The study affirmed anecdotal observations of people in Southwest Colorado, who grapple each summer with heavy recreational use — and the related wildfire risk — in the 1.8 million-acre San Juan National Forest.

Locals like Zachek have seen more people than ever flock to the treasured region of high peaks and alpine valleys for the hiking, camping, fishing, mountain biking and off-roading. That’s come with a challenge: many new visitors, he said, appear not to come prepared for a safe trip to the San Juans. “I would say it’s been challenging for the locals to get out-of-towners on board with trying to tread lightly and ‘leave no trace’ practices,” he said. “I think it just comes with the volume that we’re having.”

That means trails like Ice Lakes are typically more crowded, campsites are harder to find and sometimes visitors build campfires that escape the ring, burning portions of national forest.

Jian Chen, an associate professor at the University of North Alabama, co-published the study with former graduate student Adam Benefield. The pair used a statistical analysis of more than 1,600 wildfires and found that, when humans did start blazes, they tended to be in remote areas but near access points such as roads and hiking trails.

The burden, they say, is on visitors. They specifically called out “mismanagement of campfire and overnight camping activities” and an overall “lack of outdoor etiquette being practiced by outdoor recreators on public lands.”

A scene from the Spring Creek Fire in southern Colorado during the summer of 2018. (Handout)

Advocates told The Sun that many visitors to the San Juans don’t have enough experience to safely use fire in the burn-prone mountain range.

“I would 100% agree that people maybe don’t know and don’t understand their impact,” Adriana Stimax, education director for the San Juan Mountains Association advocacy group, said of the study. She said the summers are often so dry that, “if you flick your cigarette butt, you might start a fire.”

Much of Stimax’s job involves teaching visitors fire etiquette. The work is necessary: Humans start the vast majority of wildfires in the U.S. as a whole. A lit cigarette butt, an idling car and a downed power line can all ignite dry vegetation.

But in the San Juan National Forest, the vast majority of wildfires are sparked by lightning. Historically, most wildfires started by people in southwest Colorado also don’t grow very large, said Cary Newman, fire management planning specialist with the U.S. Forest Service. That’s in part because Forest Service personnel spend much of the summer smothering small blazes in the San Juans. The agency’s internal data, which the Alabama-based researchers drew from, also pegs about a quarter of its wildfires to human activity.

Newman said it’s “always” possible that a spark could blossom into a serious, destructive blaze. A worst-case scenario is the 2018 Spring Creek fire, sparked when a Danish man near La Veta grilled his food over a fire pit despite a countywide burn ban. The blaze mushroomed into the third-largest wildfire in state history, burning 156 square miles and 149 homes. Scientists note that, as Colorado’s climate becomes warmer and drier, fires can spark easier and burn larger.

Firefighters on Ice Lake Trail in the San Juan National Forest on Oct. 24, 2020. The Ice Fire started about 75 feet from the trail and is believed to have been human caused. By the time the fire was declared contained it had burned about 600 acres of high elevation forest. (InciWeb)

Forest Service staff are tasked with patrolling the crowded region and, so far, they say they’re successfully smothering the human-induced wildfire threat. During busy stretches of summer and fall, personnel patrol crowded camping areas in a pickup truck armed with a small water unit to fight small wildfires. They also put out campfires when they’re illegally-built during burn bans. It’s an increasingly important job; the San Juans became even more crowded after 2018, officials said, which the study doesn’t capture.

Like much of the West, the area saw a surge in visitation during the pandemic as people searched for ways to safely leave the house. From state parks to ambitious trails like Ice Lakes, an 8-mile loop at high altitude, they found the outdoors.

“In 2020, things were just booked,” said Jonathan Erickson, recreation program manager for the San Juan National Forest. Officials are also busy pushing a public relations campaign emphasizing safe fire practices.

Benefield, the Alabama researcher, said it’s reasonable to assume that recreators are also sparking fires in similar fashion elsewhere in the Rockies. The San Juan National Forest shares burn characteristics with both more northern and more southern portions of the Rockies, according to the study.

Newman, who has decades of experience assessing fire behavior, thought that the San Juans might be more fire-prone than the more northern, mountainous areas of Colorado. Even so, he said preventing “unwanted” fires is a priority for land managers across the West.

It’s unclear whether the fire trend is dovetailing with mounting homeless encampments in national forests , including in southwest Colorado. The 18-year study didn’t specifically look at that factor, and Stimax, the etiquette advocate, said the biggest risk is probably hikers and campers who don’t know how dangerous it can be to have a campfire and think, “I just want to have my s’mores.”

Experts told The Sun how campers can prevent their campfires from escaping the fire ring:

  • Consider not having a fire, even when there’s no fire ban.
  • Build reasonably sized fires.
  • Use existing fire rings. Don’t build new ones.
  • Prepare for wind in the fall and spring. Sparks can catch the wind and travel to a burnable patch.
  • Coals can smolder for days. Empty a jug of water on the fire and bury it with at least an inch or two of soil. Check in the morning to make sure it’s not still warm.
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