The bulk of the collection is letterbooks (1880-1901), dealing primarily (after 1883) with the affairs of the Thatcher Brothers Banking Company; also includes materials concerning the L.D.S. Church in Cache Valley, the Logan L.D.S. Temple, the Utah and Northern Railroad, Logan City Government, and the Democratic Party. Personal materials include correspondence with plural wife, Fanny, and son, George, and provide information on the inner workings of the institution of plural marriage. The miscellaneous papers are largely of a financial nature, and include papers of Noble Warrum, R.W. Sloan, Edward E.H. Holden, and several mining companies. Also includes class notes and missionary journal of George W. Thatcher Jr. promoting the Young Men's Mutual Improvement Association (YMMIA) in southern Utah and commonplace book of Jean C. Thatcher.