Series I: Correspondence, 1839-1958, undated

This subseries includes letters from Lockley's friends, family members (especially in Montana and Hawaii), colleagues, and readers. Material concerns personal matters, Lockley's columns and publications, rare books and book sales, Western history and reminiscences, and travels. Also included are several letters from Lockley's grandson, Neil Lockley, a sergeant in the Air Force serving in Korea, 1951. A number of items in this subseries are annotated by Lockley.

This subseries contains letters, and copies of letters, from Lockley to various friends and family members. Topics include travels, rare books, Western history, and the death of Lockley's daughter, Hope, in 1920. Also included are several letters from France in 1918, written while Lockley served as a war correspondent, and two letters written from Nome, Alaska in 1900.

Includes letters to and from various family members, including Lockley's mother, grandmother, and sister. Also included are a few letters to and from Lockley's son, Lawrence, and a set of correspondence between Lockley's father, Frederic E., and mother, Elizabeth Campbell.

Letters between Lockley and R.W.G. Vail, director of The New-York Historical Society, many of which concern donations.