(Dewey Livingston)

A technician sporting a bowtie, a pocket protector and a souvenir belt buckle stands proudly in front of an array of radio transmitter devices. A dentist wearing a bolo tie poses formally in a waiting room before a model locomotive in a glass case adorned with potted plants. A weathered man in coveralls, on his last day on the job, squints amiably from his post between the gas pumps at the old service station in Point Reyes Station. Each of these portraits marked the end of an era somewhere in West Marin, and they were documented by Dewey Livingston. The accomplished local historian is also a lifelong photographer and is mounting an exhibit of 20 of his own prints at the Stinson Beach Library, where his wife, Kerry, is librarian. The film portraits, some captured with a large-format camera, date as far back as 1970, when Mr. Livingston, then a senior at Redwood High School, captured Cesar Chavez speaking to Marin Independent Journal workers on strike in San Rafael. “I do see a little place in history for some of these images, whether it be family history or local history,” said Mr. Livingston, who lives in Inverness. His eye was often trained on the final days of a long career or the death knell of an aging place, like the last radio technician at the now-closed R.C.A. transmitting facility in Bolinas, or the final days of the practice of the Fairfax dentist who still used belt-driven tools and made his own false teeth. “When I know something’s about to change, I like to run out and take a photo,” Mr. Livingston said. But along with moments like these, he also documents his own life and those closest to him with tenderness and precision, telling a personal history made up of carefully framed portraits of everyone from fellow high schoolers in the 1970s to his own children and grandchildren. The library show, which will open with a reception on Dec. 10 and stay up through the end of the month, is Mr. Livingston’s first real effort at sharing his collection, which has been “sitting in the closet for so long,” he said. But it won’t be his last: He plans to show a much larger array of his work at Toby’s Feed Barn next year.