The 10-inch reptile, found at a U.S. 95 rest stop in Idaho, has thrived at the Kiwani Wambli wildlife rehabilitation center north of Spokane since July but is unlikely to do so well with the onset of fall, center operator Dotty Cooper said.
"It's just way too cold," she said.
Cold-blooded desert tortoises are unaccustomed to temperatures below 40, much less when the mercury dips to freezing temperatures. To survive a winter in Cusick, Sadie would have to be kept indoors for months.
She has shared a pen with an orphaned fawn. Sadie even showed the fawn how to forage for greens to eat - a process much harder for humans to demonstrate, Cooper said. The duo once wandered off after the tortoise burrowed under a plastic fence.
"When I got home, she and the deer were marching down the road," Cooper said.
The fawn has been released into the wild, which isn't an option for Sadie at this time because of the possibility that she's acquired a disease that could be passed on to others of her kind.
"Once they've been touched by humans, they're now a domesticated pet. They're no longer classified as a wild animal," said Ginger Wilfong, of the Bay Area Turtle and Tortoise Rescue in Castro Valley, Calif., east of San Francisco, which is helping Sadie find a home.
Coincidentally, Wayne and Lee Ann Cusick happened to read a newspaper story about the tortoise living in Cusick. The couple said they would like to adopt Sadie, but are reluctant to drive from their home in Blythe, a desert city in southern California, to pick up the tortoise in Washington.
Cooper and Cusick are hoping a big-hearted southbound traveler can give Sadie a ride. Cusick said he even considered a tortoise relay and is willing to make the four-hour drive to Los Angeles if someone would bring Sadie that far south.
"I somehow don't think that's going to happen," he said, "but I'm hoping that between word-of-mouth and some notoriety, we'll be able to find someone."
Adopted tortoises are common backyard pets in Blythe, Cusick said. Sadie would even have a playmate at the Cusick household: Speedy, a younger tortoise about half her size.
Desert tortoises mature at 14 and 20 years of age and typically live 60 to 100 years. The U.S. Fish and Wildlife Service designated the species as threatened in 1990, and several states provide additional protection.