Designer, Gilbert Stanley Underwood, Architect, Los Angeles, CA, c. 1923-1929; Senior Landscape Engineer, National Park Service, 1920s; Hull also worked as a member of Stephen Mather's staff in the National Park Service at the same time. He was an important conduit by which architectural commissions were directed to Gilbert Stanley Underwood. Hull collaborated with Underwood on visitor lodging at the National Park Service's Ahwahnee Hotel, Grand Canyon Lodge and Zion Lodge.