Sketch of General Riley's route through the mining districts : [of California] July and Aug. 1849 / copied from the original sketch by Lt. Derby in the office of the 10t. Military Dept. by J.Mc.H. Hollingsworth, Asst.Derby, George Horatio, 1823-18611850]Appears in U.S. 31st Cong., 1st Sess., 1850, House Ex. Doc. no. 17. Message to the President.Library's copy folded in cover 21 x 13 cm. and carries bookplate of Frederick William and Carrie Sperry Beinecke.Relief shown by hachures.Spine title on Library's copy: Map of General Riley's route, 1849.cartographic