The wildlife policy of the National Park Service has evolved gradually, and is based upon long experience in preserving areas of outstanding significance. It has been determined that animals shall not be encouraged to become dependent upon man, and their presentation to the public shall be wholly natural. Every species shall be left to carry on its struggle for existence unaided, unless it becomes endangered, and no management measure or interference with biotic relationships shall be undertaken prior to a properly conducted investigation. Numbers of animals must not be permitted to exceed the carrying capacity of the range available to them. Predator species will be given the same protection as all other animals, except in special instances where a prey species is in danger of extermination. These principles, and others, control the actions taken with respect to wildlife, and assure the continued existence of native wildlife in our National Parks. Chapter XIV GENERAL ADMINISTRATION Nathaniel P. Langford was appointed Superintendent of Yellowstone National Park on May 10, 1872. No salary was allowed, but nothing daunted, on July 4 he arranged to join the Snake River detachment of Dr. F. V. Hayden’s second expedition. This party employed as guide one Richard Leigh, better known as “Beaver Dick.” This picturesque squaw man and his wife, Jenny, with her brood, not only acted as scout but also as friend and entertainer. “Beaver Dick” knew the Tetons and south Yellowstone country like a book, and he regaled the company with many tales of hair-raising experiences in the wilds. They were respectful in the presence of one of the last genuine frontiersmen of the West. The new superintendent was characteristically indefatigable in his reconnaissance during this journey. Making personal side trips, he climbed the Grand Teton, called on Gilman Sawtelle at Henrys Lake, and joined Hayden in the Upper Geyser Basin by mid-August.[288] On this expedition the reports of much petrifaction along the East Fork of Yellowstone River (now called Lamar) were confirmed. Many trees were found that were filled with beautiful crystals of amethyst. Several species of trees that do not now grow in the Park were also found in a petrified state. Among these were magnolias, sycamores, aralias, oaks, and ferns in abundance. This, and subsequent investigations, disclosed an interesting story of climatic change. Obviously Tertiary flora was of a Southern type, and Yellowstone’s climate in that time was comparable to southern California’s today.[289] [Illustration: Photo by IV H. Jackson _“Beaver Dick” (Richard Leigh) and family, 1871_]