After receiving a liberal arts education at the Munro Academy in Elbridge, New York, and a stint in the U.S.-Mexican War, James Henry Martineau spent his life as a surveyor, civil engineer, clerk, mapmaker, and pathfinder in Zion. After becoming a Latter-day Saint in 1850, Martineau went with Apostle George A. Smith to settle Parowan in southern Utah, with a commitment to building God's kingdom in the West. As a leader in the Utah Territorial Militia he conducted military drills, witnessed events surrounding the Mountain Meadows Massacre and the legal trials of its perpetrators, explored wilderness areas, submitted reports, and drew maps to record his travels throughout the entire Mormon corridor. ​ These journals document his exploration of virgin lands in southern Utah, his laying out of townsites and farmland in Cache Valley, his participation in canal building and water projects in Arizona, and his near-death experiences while surveying rough, mountainous areas. His work for the Union Pacific Railroad through Weber Canyon and across the Salt Lake Promontory and Humboldt Desert in 1868 is one of the very few complete records of its kind.