Bit by painstaking bit, nature is being reclaimed at the canyon, located at Almond Street and Skyline Road in Rancho Cucamonga.
"We try to clean up a section and move on, and everything we can get to by foot, we've been working on and it is. We've been making a difference," said volunteer Doug Price, who was cleaning off graffiti from rocks along the canyon path.
Price is with the Cucamonga Foothill Preservation Alliance. He can recall a time when such graffiti was not a common sight. Then in 2009, it seem to change.
"It became a social media event, so to speak, and numerous people started entering the canyon," said Eric Noreen with the Rancho Cucamonga Fire Department.
That's when calls to the fire department spiked. Residents also began to notice something else.
"People started coming and leaving trash, tearing up the canyon, graffiti. We would be walking and stepping over wet paint," Price said.
In August 2013, the U.S. Forest Service shut down the canyon for fire and safety reasons. That allowed volunteers to start the cleanup.
"All over the side of this wall, also this huge rock," described Shanna Shaw, who pointed to each rock she has personally covered or cleaned up.
Shaw said she hopes to one day bring her children back to the canyon.
"It's beautiful right now. Compared to what is has been, it's amazing," Shaw said.
Now, there's no more trash along the creek. Next, the group wants to tackle the falls. This is a complicated job because of the location.
"We don't know what's going to happen when they open the gates and allow the masses back in," Price said.
Much of the graffiti may be gone, but there is still much more work left to do.