“I am writing to inform you of my decision to resign as Director of the Seattle Art Museum effective June 30,” goes Derrick Cartwright’s letter on the Seattle Art Museum site. “This was a difficult decision for me but with SAM today in a much stronger position than when I arrived, I believe the time is right for a change in leadership.”

Cartwright, who will have lasted just two years at SAM’s helm, goes on to list some highlights from this year: nearly 600,000 visitors to SAM downtown, membership at an all-time high, the success of the Picasso exhibit, and “stabilization of our financial situation and real estate dilemma.” (The Picasso exhibit alone was, according to a study commissioned by SAM, to have generated an “estimated $66 million in economic impact for Washington State, of which $58 million was generated in King County.”)

The news is surprising and sudden, but SAM’s leadership is trying to put a brave face on:

We are very appreciative of Derrick’s achievements and service to SAM. He is a great ambassador for the arts and we wish him the best in his future pursuits. Derrick will continue to make significant contributions to the art world. –Charles Wright, Chair of SAM’s Board of Trustees

Wright and SAM’s Board President, Maggie Walker, will share “executive oversight” while the Board looks for a new director. This is not a situation any museum would like to be in, if they had a choice–executive succession wants to be seamless, a trusted hand at the tiller until buzz can be generated over a lineup of fresh candidates. Cartwright says he’ll depart June 30, 2011, but the board has asked if he’ll remain a consultant until September 2012.

There’s the smell of recessionary burn-out from Cartwright’s letter: “I am eager for a break and for the chance to undertake my own projects,” he writes, before saying he hopes to spend more time with his family. He says that with his attention no longer demanded by “urgent administrative and financial challenges,” he hopes to reconnect with his passion for art history.