Dr. James L. Tyson sailed from Baltimore for California in January 1849, crossing the Isthmus and sailing on to San Francisco. Diary of a physician in California (1850) recounts his 1849 tour of the Northern Mines in search of a likely place for his medical practice and his hospital at Cold Spring, where his patients included a number of Oregonians. Tyson closes his hospital at the end of the summer, sailing from San Francisco as a ship's physician, crossing the Isthmus and landing in the United States in December 1849. His diary pays special attention to miners' health and working conditions.