The terrier, Ana, spent Sunday night on top of the still snow-covered mountain, KING-TV reported.
Mount Si, 4,167 feet above sea level, is a popular hiking spot in the Seattle-Tacoma region. The mountain has a rocky summit with no trail known as the Haystack.
The owner called the King County Sheriff's Office late Sunday afternoon to report that her dog, apparently spooked by something, had raced 200 feet up the Haystack and refused to descend, the report said. The Washington State Animal Rescue Team responded but decided it was too late to bring the dog down safely that night.
In the morning, a Seattle Mountain Rescue team climbed the peak, secured Ana in a harness and lowered her from the mountain.
"These rescue teams are amazing," the owner said. "These people drop whatever they are doing to volunteer their time to save humans and animals alike."