 After three years of work on the third volume of Forbush's book, Broun in 1929 went to work creating the Pleasant Valley Bird Sanctuary.There from 1929 to 1932 he cut six miles of trails and built a nature museum.While he was at Cape Cod, he met Irma Knowles Penniman (1908–1997), an ornithologist and conservationist, and married her on 15 January 1934.