Jessica Hayes of Aurora said her 4-year-old son, Dylan, climbed atop her couch to talk to her downstairs neighbors through the window and fell through the screen, KCNC-TV, Denver, reported Monday.
"I was terrified," Hayes said. "I didn't know what I was going to see when I got down to the ground floor."
The mother said she was shocked and relieved to discover Dylan had landed on his feet on the rocks below.
"I feel beyond lucky. There must have been something watching over Dylan that day," she said.
Dylan spent about 20 hours in the hospital and wore a neck brace as a precaution, but doctors said he did not appear to have any serious injuries.