President Theodore Roosevelt's love of natural history is celebrated in two sketches written by renowned naturalist John Burroughs. The friends shared a two-week trip to Yellowstone in the spring of 1903, in order to observe the wildlife and geologic wonders of America's first national park. The desire was to commune with nature, not to hunt. "I will not fire a gun in the Park, then I shall have no explanations to make," President Roosevelt said. While they had guides, the president was unaccompanied by secret service, personal physician, or secretaries and, remarkably, took an 18-mile trek through hard country completely by himself on one occasion.  "He came back as fresh as when he started…"