 The agency also made expense and payroll mistakes which cost him money, He tendered his 11-word resignation on August 12, 1906 which also ended his work at Henninger Flats.Lukens made several trips to Yosemite National Park, each time his interest in every aspect of nature intensified, and led to research, correspondence and interviews with experts for whom he collected various specimens and photographed specific items.Lukens joined the fledgling Sierra Club in 1894 after a visit to Yosemite and the Sierra Nevada Mountains.