Here it is, in documentary form, the Greatest “Show Must Go On” Story Ever Told.

Richard Green’s “I Know Catherine, The Log Lady” is a moving appreciation of the long life of a working actress, a woman rendered immortal by her quirkiest role, thanks to the fanatical fans of David Lynch and “Twin Peaks.”

But playwright Robert Schenkkan credits Catherine E. Coulson with inspiring his Pulitzer Prize winning epic play “The Kentucky Cycle.” For years, she was a mainstay of the Oregon Shakespeare Festival, which is where they met..

Coulson spent much of her Hollywood career in demand behind the camera as the rare female focus puller/union camera assistant, with the likes of Nicholas Meyer praising her work on his “Star Trek: The Wrath of Khan.”

And Lynch, who gave her that obituary-headlining role, remembers Coulson’s pivotal place in his life and career. He “discovered” her and others in the cast of actors from the San Francisco troupe “The Circus,” several of whom spent years with him making his debut feature, “Eraserhead,” with Lynch lauding Coulson’s in front of and behind the camera efforts in making the eccentric Lynch the film icon he came to be.

“Twin Peaks” fans will love this documentary for the deep dive into creating that singular character and her place in that show’s mythos. After the show and later “Fire Walk With Me” movie wrapped in the ’90s, Coulson was the fan convention attendee who kept the “Peaks” flame alive through the show’s 2017 revival for Showtime.

But after two acts of friends, neighbors and co-stars like Kyle MacLachlan, Michael Horse and Kimmy Robertson sing Coulson’s praises as the series’ version of “The Oracle of Delphi,” Green focuses on something he teases in film’s opening moments.

Coulson was diagnosed with stage four breast cancer just before the last iteration of “Peaks” went before cameras. She made that her life’s last goal — reuniting with her friend, collaborator and fellow transcendental meditation devotee Lynch to “finish” that saga’s story was her reason for staying alive.

A legion of friends, health care givers, actors and even a helpful journalist and accomodating mortuary representative made that their cause, as well.

There are unpleasant reminders of personal tragedies and assorted unhappy relationships, including an abusive marriage to “Eraserhead” star Jack Nance mixed in with the wide array of “everybody loved her” declarations by co-workers, friends and one ex-husband devoted to her.

But it is the film’s depiction of a gutsy trouper determined to get that last performance in that makes this “Log Lady” appreciation sing.

Lynch talks up the transcendental meditation that they had in common, reflects on death and plays his part in making her dying wish come true. And the viewer hears the death watch stories of those closest to Coulson, wondering how on Earth that final appearance was ever going to come off.

As the cliche goes, this film is both sad and life-affirming in its depiction of end-of-life concerns.

What makes it special is the amusing life-spirit who came to embody “Lynchian” with her inscrutable presence, the way she passed along the cryptic wisdom of her pronouncements — “I do not introduce the log,” which she cradled so inscrutably, and her appreciation of all that her longtime friend David Lynch knew, loved and taught her about “Ponderosa Pine.”

Rating: unrated

Cast: Catherline E. Coulson, David Lynch, Kyle MacLachlan, Timothy Near, Miriam Laube, Michael Horse, William Haugse, Mindy Alper, Deborah Satterfield, Kimmy Robertson, Armando Duran,
Robert Schenkkan, Nicholas Meyer and Mark Frost.

Credits: Directed by Richard Green.

Running time: 1:49

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