Atsumi Yoshikubo, 45, was last seen Oct. 22 walking along a highway outside the city. Staff at a hotel reported her missing a few days later after she failed to check out of her room.
Const. Elenore Sturko said Tuesday that police came to the determination about her fate after nearly a week of extensive searching.
"She did have a plan to go into the wilderness alone and become a missing person," Sturko said. "Our investigation has also revealed Yoshikubo took steps to avoid being found."
Mounties initially said Yoshikubo's room at the Explorer Hotel had been left in a state suggesting she intended to return.
There was also no evidence of foul play.
Police and civilian volunteers, with the help of dogs and aircraft, searched the area for about a week, including remote tourist attractions along the highway and other hiking areas.
Sturko wouldn't reveal what new evidence has led investigators to believe the tourist wanted to disappear into the bush, or how she may have died.
She said the search has been stopped and the coroner's office is now in charge of the case.
"But the investigative file will remain open and we'll follow up on all leads of hopefully, eventually, locating Yoshikubo's remains."
RCMP have updated Japanese consulate officials, who are in touch with the woman's family, Sturko said.