Given that the people of the Pacific Northwest are not a homogeneous group, there is, naturally, variation in their versions of the fire-acquisition story. It seems, though, that they all agree that an animal stole fire from a mountain and brought it to humankind, much like in the myth of Prometheus (though there is surely no direct connection with Greek myth here).
Three versions of this story are collected by K. B. Judson in Myths and Legends of the Pacific Northwest. According to the Nez Perce, it was Beaver that stole fire; while according to the Achomawi, it was Dog; and according to another group (perhaps the Shoshone?), it was Coyote.
Here is an excerpt from the story about Coyote, which contains the word "Skookum".
Then Coyote seized the fire and jumped down the mountain side. Quickly
Skookum followed him. She caught the tip of his tail in her hand; therefore it is white, even to this day. But Coyote reached Wolf. Wolf seized the fire and leaped down the mountain. Skookum chased Wolf. But Wolf reached Squirrel. Squirrel seized the fire and leaped from branch to branch down the mountain. The fire was so hot it burned the back of his neck. You can see the black spot there, even to this day. The fire was so hot it made Squirrel's tail curl up over his back. Skookum chased Squirrel But Squirrel reached Frog. Frog took the coals of fire in his mouth and hopped away. Skookum chased Frog. She caught his tail in her hand. Frog jumped away but Skookum kept the tail. That is why frogs have no tail, even to this day. Soon Skookum caught up with Frog again. To save the fire, Frog spit it out on Wood. Wood swallowed it. Skookum did not know how to get the fire out of Wood. But Coyote did. Coyote showed the Indians how to get fire out of Wood by rubbing two dry sticks together, as they do even to this day