TUCSON (KGUN9-TV) - Sabino Canyon gets hit hard during Monsoon. Over the years, heavy rain moves boulders and floods trails.
Bob Raffa and Gary Youngling are volunteers with the U.S. Forest Service.
Raffa and Youngling say Sabino Canyon has changed over the years because of heavy rains.
"You can hear it coming you know its like what's that sounds," Raffa said. "It sounds like thunder on a nice day, and then you go, 'Oh yeah maybe it's water coming down,' so they have time to get out."
They said heavy rain took out a bathroom back in 2006.
"Remember it is not the water," Youngling explained. "It's the Volkswagen boulder that is pushing so you have to really be careful."
They advise hikers pay attention to the weather and clouds because the weather can change abruptly during monsoon.
What's left from the heavy flooding from last year? A physical reminder of how high the water gets.
"This all came down and was floating on top and then it just got trapped in the trees here, so the water height was this high," said Raffa. "I was standing in a dry creek bed, and I filmed the water coming down three and half minutes, and it was up to my knees, and it was about 25-30 feet across."
They said last year the monsoon had more than seven inches of rain.