If you've hiked around Boise's foothills, you've likely come across a pile or two of dog poop. In February, there were 104 piles of waste at the Table Rock trailhead. Data show (yes, it's being tracked) those piles fluctuate from year to year, but the problem persists.

Sam Roberts says he sees lots of dog waste on his travels. He and his gray weimaraner, Sunny, are headed back from a hike along the Ridge To Rivers Trail System. As a responsible pet owner, he says he picks up what Sunny leaves behind. He’s got not one, but two plastic bags at the ready. “Just in case she has to go twice. Which is rare, but it happens from time to time," he says.

The pair come up to the foothills three or four times a week. "It’s not very aesthetically pleasing to the trail user to see collections of dog feces, collecting in various places so, I’m not a fan of it.”

Julia Grant isn’t either. She’s Boise’s foothills and open space manager. One part of her job is tracking dog waste from year-to-year in parts of the foothills. “Someone suggested to me that you use sprinkler flags so people could see where this dog waste was," she explains. "So that was February of 2008 and at Lower Hulls Gulch there was 141 piles of dog waste between where people park and the first trash can.”

Each February, Grant puts a red sprinkler flag on each pile of dog poop at the same three trailheads: The Old Pen going up to Tablerock, the Corrals trailhead up Bogus Basin Road and Lower Hulls Gulch, where things have improved since 2008.

“It went down tremendously the next year, it was down to 49," she says. "And then it’s kind of gone up and down and up and down and this year was 61. But it never has gotten above 100 again at Hulls Gulch, so that’s encouraging.”

The Table Rock trailhead was a different story. The count has gone up steadily there for the past four years. In February 2013, Grant counted 136 piles of dog waste.

It may be poop, but it’s not good fertilizer for the foothills. Wild animals have evolved with the environment, eating local vegetation. But dogs aren’t part of that natural ecosystem. Plus, dog waste can contain fecal coliform, roundworms, strep, salmonella, and giardia. Concentrated in places like the Hulls Gulch trailhead, it can filter into water sources. “When it rains, this waste goes into the Boise River and that’s not good for us as humans and it’s not good for the other wildlife that enjoy this area," says Grant.

There’s another problem: foothills managers spend a lot of time trying to keep the native plants in and the invasive species out. Native grasses thrive in the area’s low-nitrogen soil. But Grant says dog waste is high in nitrogen and when it’s left on the trail.

"That creates a high nitrogen environment and invasives love even more," according to Grant. "So, the invasive seeds want to go right next to the trails, they want to push out the native grasses and then they want to move on further into our natural environment.”

Leaving dog waste behind is not only bad for the ecosystem, it’s against Boise city code. It’s illegal within city limits. The foothills are a partnership of lands from different agencies, including Boise city property. That means for some of the foothills, including most trailheads, hikers need to be prepared, like Sam Roberts with his plastic bags. “I think it’s a pretty simple thing for people to kind of pick up after their dogs, doesn’t seem like a big thing to ask," he says.

For Julia Grant, the key is education. Until she started putting up red flags, many people told her it just wasn’t that big of a problem. But she says once people see the red flags, they start thinking differently. In the end, it’s up to each individual owner to make a difference.

Here’s a positive note. Grant says there are 44 trash cans along the 150 miles of pathways in the foothills. When those cans are emptied, a majority of the trash tends to be plastic doggy bags full of waste.

“There’s not a poop fairy," Grant says. "You really need to take the responsibility as the owner. Your dog doesn’t have opposable thumbs, it can’t pick up its own waste.”

Copyright 2014 Boise State Public Radio