The Playwrights Horizons revival of last summer’s Clubbed Thumb hit production has received almost unanimous critical acclaim. The Times made it a Critic’s Pick and it has been extended by popular demand. Playwright Jaclyn Backhaus's subject is the famed Powell expedition of 1869, during which 10 intrepid men in four small boats set out to traverse the Green and Colorado Rivers from Wyoming to Nevada and become the first white men to travel the length of the Grand Canyon. The top-notch cast, ably directed by Will Davis, recreates the rhythms of daily life, the rivalries, the insecurities, the dangers and defections the group endured. The perils of sailing through white water is memorably captured by effective choreography. The play’s gimmick is that all the roles are played by women. Its sensibility is archly contemporary, rather than historical. For the first twenty minutes or so, this worked for me. However, the play soon became repetitive and cartoonish. It eventually seemed like a very long pointless skit that trivialized its subject and wore out its welcome long before it ended. I will grant that the cast was uniformly good, the scenic design by Arnulfo Maldonado was attractive and the costumes by Asta Bennie Hostetter were apt. The audience seemed to love it; the young woman next to me broke into uproarious laughter at least once a minute. I wish I had been able to join in the approbation. Perhaps I would have been less disappointed if my expectations had not been raised so high by all the praise. Running time: 95 minutes, no intermission.