The woman, who was in her 40s, was using a toilet at the top of Mt. Walker when she dropped her cellphone down into the vault, the Brinnon Fire Department said.
She attempted to take the toilet apart, disassembling the seat and housing and used her dog’s leash to fish out the dropped phone, according to authorities.
When the woman used the leashes to help support herself, fire officials said the leashes failed, and she slid headfirst into the vault. After spending nearly 20 minutes trying to climb out, she used her cellphone to call 911.
Brinnon and Quilcene firefighters responded to the mountaintop around 3 p.m. and made a "makeshift cribbing platform" tall enough for the woman to stand on and pulled her to safety, fire officials said.
The woman was not injured during the incident.
"The patient was extremely fortunate not to be overcome by toxic gases or sustain injury," the fire department said.
Rescuers washed the human waste off her and gave her a disposable Tyvek suit to wear, officials said.
Despite firefighters encouraging the woman to seek medical attention after being exposed to human waste, officials said she declined and continued back to California.