Georgia O’Keeffe flashes a devilish smirk from beneath the brim of a black hat; beside her is a lanky cowboy, also black-hatted, suppressing a laugh. It’s a pretty cool snapshot, cooler still because it was taken by Ansel Adams, an artist known for an ¾sthetic that’s about as far away from point-and-shoot photography as you can get. This and several other informal shots taken by Adams during a month-long fall camping trip through the Southwest in 1937 are on display at the Fitchburg Art Museum through January 12. The trip commemorated in ÒAdams and O’Keeffe on the RoadÓ was organized by financier and arts patron David Hunter McAlpin (who funded the founding of the photography department at New York’s Museum of Modern Art). The fellow campers included McAlpin’s cousins Godfrey and Helen Rockefeller along with Orville Cox (the man in the black hat), who was head wrangler at New Mexico’s Ghost Ranch, where O’Keeffe maintained a studio.

In 2001, the heirs of McAlpin’s widow, Sarah, discovered a box of some 300 small-format proofs of pictures Adams took on that trip. Seventy-five of them — most of them studies of landscapes, native Americans, and primitive architecture — were assembled for this show by Stephen Jareckie, the retired curator of photography at the Worcester Art Museum, who’s now working with FAM.

None of the images in the proofs displayed became part of Adams’s Ïuvre, though the show includes what amount to prototype shots for his 1942 White House Ruins, Canyon de Chelly homage to 19th-century photographer Timothy Sullivan (a finished print of which is displayed, along with a few other full-format later works). The proofs are small, flat, and murky — three qualities Adams never abided in his finished work. Yet ÒAdams and O’Keeffe on the RoadÓ is well worth the trip to Fitchburg, and for three reasons. The first is the museum itself, which is charming to a fault and generally overlooked by audiences east of I-495. Then there’s the role this trip and these photographs played in Adams’s career. At the time he and O’Keeffe hit the road, it had been only 10 years since Paul Strand had turned Adams on to photography’s artistic potential, and only seven years since Adams, at age 28, had adopted the medium as his life’s work. He had already published a manual, Making a Photograph, and been exhibited by Alfred Stieglitz in New York. His most artistically significant work was ahead of him, and some of it focused on sites he visited on this 1937 expedition. Proof quality aside, most of the pictures in ÒAdams and O’Keeffe on the Road,Ó are more recognizably Adams’s than not. The rough compositions, purposes, and subjects shown here are echoed again and again in refined form in his later work. Adams devotees cannot miss this opportunity to glimpse his career in progress; the casual viewer will find the proofs fascinating for their subjects and, in some cases, their historical content.

Finally, there’s the irresistible attraction of the handful of candid shots of O’Keeffe (looking unfamiliarly youthful at age 50) and company. The camaraderie of a pair of artists riding their patron’s ticket on a visual-exploration spree comes through. As do the rigors of the trip and the sometimes inhospitable environment. We see O’Keeffe perched above Utah’s San Juan River with a sketchpad on her lap. We see a car struggling along a deeply rutted road. We see Adams’s shadow projected on the landscape he’s photographing. We do not see Georgia O’Keeffe posing in front of her station wagon at the Grand Canyon, but we wish we did.

The Fitchburg Arts Museum is also displaying, through January 12, a collection of Eliot Porter’s almost-too-perfect color nature photos. The museum, at Merriam Parkway in Fitchburg, is open Tuesday through Sunday from noon to 4 p.m.