East Brother Island is a 1-acre rock in San Pablo Bay that is the site of an inn housed in the 1874 lighthouse. (Frederic Larson / The Chronicle)
Elan Stewart, 30, has been lighthouse keeper on East Brother Island for the past three years, along with his wife, Katy Stewart, 32. (Frederic Larson / The Chronicle)
Katy Stewart strolls with her son Drake. The Stewart family's nearest neighbor is the harbormaster at Point San Pablo Yacht Harbor, a 20-minute boat ride away. (Frederic Larson / The Chronicle)