Second Valley, the Inverness neighborhood between First Valley and Seahaven, has been a bit neglected, history-wise. “Jack Mason wrote extensive histories of Inverness but—bless his heart—virtually ignored Second Valley,” wrote historian Dewey Livingston, who is curating an exhibit at the Jack Mason Museum of West Marin History to document the neighborhood’s first 80 or so years. The valley’s initial European inhabitants ran a dairy there, starting as far back as the 1850s; it was originally near the foot of the valley and, later, on Cameron Street. For years, a gate at the entrance of a dirt path that is now Vision Road held the Second Valley cows in, while keeping outsider cows away. The valley featured a busy waterfront, with three piers, a beach and a bathhouse. Eustace Bellman, a carpenter and early resident who built one of the piers, ran a boat launch. Valley homes were built as summer getaways starting in the late 1800s, and residents sold baked goods like Scottish breads and Johnny cakes to neighbors, cultivated elaborate gardens and, in one case, literally split one house into two over a dispute. According to Mr. Livingston, local lore posits that Presbyterians settled in First Valley while Catholics settled in Second Valley. Although it is difficult to know how true that is, many people with Scottish, British, Irish and Portuguese heritage lived in the valley into the 1940s. The Boy Scouts also ran a summer camp on the cow pasture in the 1920s, performing skits for locals on weekends. When the camp relocated, people began to buy lots and build houses at the former dairy, and development displaced a tidal lagoon once at the foot of the valley. After the 1940s—when Mr. Livingston’s exhibit ends—the neighborhood expanded into the hills. Starting in the 1950s, more people lived in the valley full time, although Mr. Livingston, himself a Second Valley resident, guessed that about half of the homes are only occupied during summer. “It still retains its sense of isolation, I think, from mainstream Inverness. It’s a little off the beaten track,” he said. “Second Valley: Inverness’s Forgotten Neighborhood” shows at the Jack Mason Museum of West Marin History until Sept. 26 during the regular hours of the Inverness Library, with which it shares a building.