The steward of Johnny Carson’s legacy has agreed to cooperate with filmmaker Peter Jones on a major documentary regarding the latenight host for PBS.

KCET Los Angeles will be the presenting station on the project, tentatively titled “Carson,” as it was on Jones’ “Inventing L.A.: The Chandlers and Their Times.” As production is just beginning, the two-hour special isn’t expected to air until 2011 or possibly 2012.

More than five years after his death and nearly two decades since he retired, Carson’s 30-year-stint as host of “The Tonight Show” continues to cast an enormous shadow across the latenight landscape. Equally interesting, however, is how private he remained once he exited the spotlight in 1992. After having been one of the most public figures in the U.S., Carson never really performed again and largely shunned media requests.

Jones began writing to Carson about the possibility of doing a documentary on his life and career as soon as the host left NBC. Carson called him in 2003, Jones recalled in an interview, saying that while he admired the letters the producer had sent, “I’m not going to do anything, because I just don’t give a shit.”

Jones recently secured a deal with Carson Entertainment Group, which is overseen by Carson’s nephew, Jeff Sotzing, who served as a producer on “The Tonight Show.” Jones will have full access to the program, including rarely seen clips he’ll be able to cross-reference online, such as Carson discussing his childhood in Nebraska. He also plans to conduct original interviews.

“I just felt that the time was right,” Sotzing said, noting that he was a fan of Jones’ work, which also includes the Turner Classic Movies docu “Stardust: The Bette Davis Story.” He added that Carson was “always on the fence about having a biography done” in his later years but finally opted not to pursue it.

The project’s goal, Jones said, is “about preserving a legacy, not dishing lots of dirt. … Through telling his story, you also get a history of the medium of television.”

The documentary wasn’t a tough sell to KCET Prez Al Jerome, who oversaw the NBC TV station group for a decade during Carson’s tenure. In fact, he recalls being in the audience when the host delivered his bombshell announcement — that he intended to give up the show in a year — at NBC’s upfront presentation in 1991.

“Johnny Carson really defined television in so many ways,” Jerome said, calling the project “an opportunity to acquaint younger generations with someone who was so dominant in their parents’ time, and why.”

Carson Entertainment controls the rights to “The Tonight Show” as well as ancillary material such as “Carson’s Comedy Classics,” sketches culled from the series that were compiled into 130 half-hour episodes for syndication and DVD release.