This collection consists of correspondence, financial records, legal documents, and other material relating to John T. Murphy (1860s-1914), to the John T. Murphy Estate (1914-1935), and to several of the businesses which Murphy established. The correspondence of R.P. Heren, Charles Wiley, and Matt J. Roke contains much detailed information about the day-to-day operations of the Murphy ranches. Considerable correspondence also details Murphy's interests in Florida citrus groves. Another primary correspondent in the collection is Murphy's secretary, John H. Tucker, who conducted much of the business. In addition, correspondence for the estate was conducted by Albert L. Smith, trustee, and by Tucker.

Subgroups in the collection include John T. Murphy; John T. Murphy Estate; John T. Murphy, Jr.; John T. Murphy and Company; Blue Canyon Coal Mining Company/Bellingham Bay and Eastern Railroad Company; Florida Property; Jay Gould Mining Company; Montana Cattle Company; Montana Savings Bank; Montana Wool Growers Commission Company; Murphy-Maclay Hardware Company; Northwestern Cattle Company; Powder River Land and Cattle Company; S.T. Christian and Company; Teton Ranch; and Woolman and Christian.