Catherine E. Coulson, a classically trained actress who won fans as the enigmatic Log Lady in the TV series “Twin Peaks,” died on Monday at her home in Ashland, Ore. She was 71.

Her death, from cancer, was confirmed by the Oregon Shakespeare Festival, where she had acted for 22 seasons.

Ms. Coulson had a long creative relationship with the director David Lynch, a co-creator of “Twin Peaks.” He had initially cast her as a nurse in “Eraserhead,” but she ended up as an assistant director instead on that 1977 film, which became a cult classic.

Mr. Lynch is known for his eccentric characters, and “Twin Peaks,” set in a small town in Washington State, was rife with them. But none were as peculiar as Ms. Coulson’s Log Lady, always cradling her precious log, a cross between a pet and a portal to the supernatural.