It's alive!
Experiment to plant trees on mine waste a surprising success

In 2016, Gretchen Fitzgerald, a forester then with the San Juan National Forest, had a rather unconventional idea: What if we planted trees in a pile of mine waste?

As the restoration forester for the district, Fitzgerald identified one of the many areas around Silverton impacted by legacy mining in the San Juan Mountains, a site known as the Brooklyn Mine, just northwest of town.

“Looking around that site, I saw some seedlings naturally creeping around from the side,” Fitzgerald said in an interview with The Durango Telegraph this week. “So I said, ‘Let’s try it.’”

Indeed, there are almost countless sites around Silverton still feeling the effects of mining in the region, which thrived in the late 1800s and early 1900s. Mining continued with boom and bust cycles over the years, until the last mine closed in 1991.

In mining’s wake, heavy metal loading continues to dump into the Animas River, affecting water quality throughout the watershed and aquatic life. It all culminated in 2015, when the Environmental Protection Agency triggered the Gold King Mine spill, releasing three million gallons of mine wastewater into the Animas.

Ultimately, the series of events led to the EPA’s long-anticipated Superfund designation in 2016 for nearly 48 mining sites around Silverton, known as the Bonita Peak Mining District. Part of that clean-up effort included the Forest Service, and Fitzgerald started to wonder whether a tree-planting project on mine waste could restore the landscape and stabilize affected soils. It was a risk, as something like that really hadn’t been attempted before.

“It’s an experiment,” she said in 2019, the year the trees were planted in the ground.

Now, five years later, Fitzgerald has since moved onto the Sequoia National Park in California. Her trees, however, are doing remarkably well. This summer, in the first monitoring of the site since 2019, it was confirmed that nearly 100% of the trees survived and are thriving.

“It’s exciting,” Fitzgerald said. “There’s a lot of mines around there. We could expand this and do more work.”

Nasty business

The Brooklyn Mine site is located about 12 miles northwest of Silverton, off U.S. Highway 550, and is considered among the worst polluters in the Animas watershed.

According to federal records, miners first bored into the mountainside for its reserves of gold, silver and zinc in the early 1900s. The mine operated on and off over the years, with the most recent mining activities happening in the 1960s through the 1980s.

Ultimately, the Brooklyn Mine shut down, leaving behind a complicated mess to clean up.

Peter Butler, co-founder of the disbanded Animas River Stakeholders Group, said the Brooklyn Mine was included in a list of the top 33 polluting mine sites in the region. He said the wastewater coming out of the mine leaches a fair amount of heavy metals into Mineral Creek, a tributary of the Animas River.

“It’s one of the higher-priority sites,” Butler said previously. “It’s a drainage with a fair amount of metals.”

Because the mine is located on Forest Service land, the agency led some small-scale restoration projects beginning in the 1990s. But renewed attention was given to the mine with the creation of the Bonita Peak Superfund site in 2016.

That’s when Fitzgerald stepped in.

“I got this idea that we don’t have to accept this hillside of sediment and rock,” she said. “All of our efforts from mine restoration are centered on toxic mine water and not really addressing the landscape around the mine.”

Keep it local

For the project, Fitzgerald collected seeds from Engelmann spruce that were located right onsite. The seeds were then sent to a nursery to mature for two years. In 2019, about 900 spruce trees, as well as an estimated 300 flowers and 30 willows (also harvested locally), were planted by volunteers and interns.

The trees were planted directly on a pile of rock that miners would take out of the mountain and dump just outside the mine entrance. Miners would extract valuable metals, leaving behind the potentially harmful waste pile.

“It’s a harsh environment,” Fitzgerald said. “This particular site is not considered toxic, but it does have a lot of heavy metals in it. We weren’t sure if (the vegetation) would take or not.”

In the short-term, if the project were to turn out successful, the trees could help stabilize the hillside, keep waste rock out of the water and restore the landscape. Long-term, however, it could set a new precedent for future restoration projects on impacted mine sites.

“Part of it was trying to find out what kind of vegetation would grow on these sites,” she said.

However, Fitzgerald, who helped facilitate the planting of nearly 2.2 million trees across Southwest Colorado over a 20-plus-year career, left to take on a new challenge in Sequoia National Park in 2021. The project sat dormant – that is until recently.

Braving the elements

With Fitzgerald’s departure, on top of the pandemic, the Brooklyn Mine site fell to the backburner. However, Amanda Kuenzi, community science director for the Mountain Studies Institute, said there was renewed interest in the Brooklyn Mine site this spring.

“There was never a monitoring plan in place, which was unfortunate, because it would have been nice to have scientific design,” she said. “But we had been wanting to get back up there for a while.”

After securing a grant from the National Forest Foundation, MSI recently took Silverton High School students on a field trip to the Brooklyn Mine site to do restoration and stewardship work. It also provided a chance to check on the trees.

“We saw a close to 100% survival rate,” Kuenzi said. “It’s really awesome.”

A couple factors might be at play in the tree’s survival. For one, biochar (a type of charcoal made from things like wood or crop leftovers) was used to improve the soil. And, because the trees had two years to mature before planting, it’s likely they were better able to withstand the elements.

And perhaps most telling – it appears the forest was on its way to natural regeneration.

“There are baby trees of all ages up there reestablishing on that site,” Kuenzi said. “It seems like the forest is healing in that area and reclaiming the land.”

Nature’s got it from here

A few other replanting projects have been conducted on the impacted lands around Silverton, but it appears nothing on the scale of Fitzgerald’s project. Recently, the EPA and partners planted willow stakes to the beaver pond section of the North Star waste dump, just southwest of town. And, Trout Unlimited planted willows on the Ben Franklin Mine north of Silverton.

Meg Broughton, spokeswoman for EPA, said the agency is always looking for innovative ways to restore mine sites. Abraham Proffitt, spokesman for the San Juan National Forest, said he was not aware of any other Forest Service-led replanting projects.

“But personally I’m curious if it could work somewhere else,” he said. “I’m intrigued to see they survived and what it could mean for other mine sites, so I hope this continues.”

As for the long-term plan at the Brooklyn Mine, the Forest Service did not respond to follow-up requests for comment. Previously, a much larger restoration project, which included restoring adjacent wetlands, was planned at the site. But the status of those projects is also unknown.

As for the planted trees, Fitzgerald said that having a monitoring plan in place would help for research purposes. As for the trees themselves, she said nature will likely do its thing.

“They’re growing and probably don’t need anything,” she said. “They look beautiful. And it’s fun to be able to try something and to see these successes.”