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Diamond A Cattle Company Records

Identifier: MSS-355-BC

Scope and Content

The Diamond A Cattle Company collection comes from the estate of Leon E. Williams, New York owner of the Wagon Mound and South Dakota parcels of Diamond A land after the 1939 sell-off of ranch properties by the Bloom Land and Cattle Corporation. As such, most documents relate to Williams's personal and business ventures and to the daily operations of running and maintaining ranch properties between the early 1940s and 1958. The collection includes vouchers, correspondence, tax returns, warranty deeds, and general papers pertaining to the Williams' Diamond A Cattle Company business. There is also correspondence between Williams and the Regents of Dartmouth College, Hanover, New Hampshire. Williams was a graduate of Dartmouth in 1915 and a benefactor of the college throughout much of his life. In addition to the Williams material, a very few of the documents relate to business transactions of the Bloom Land and Cattle Company. These documents include warranty deeds between the Bloom Land and Cattle Corporation and Burton C. Mossman and a small map of their land holdings.


  • 1878-1956

Language of Materials


Access Restrictions

Collection is open for research.

Copy Restrictions

Limited duplication of CSWR material allowed for research purposes. User is responsible for compliance with all copyright, privacy, and libel laws. Permission is required for publication or distribution.

Organizational History

The Diamond A Cattle Company was a nationally-known ranching outfit based in New Mexico and Colorado between 1885 and 1939. The company was created in 1885 by Frank G. Bloom of Trinidad, Colorado, and M.D. Thatcher of Pueblo, CO, as a subsidiary operation to the Bloom Land and Cattle Company. At that time, The Bloom Land and Cattle Company acquired the Diamond A Ranch in Chaves County, New Mexico and the Circle Diamond Ranch in Lincoln County, N.M., combining the two ranches into a large cattle and sheep ranching outfit called the Diamond A Cattle Company. As the ranching operation grew, the Diamond A Cattle Company used lands in Chaves, Lea, Eddy, and Lincoln counties, New Mexico. Later acquisitions included ranches on the Rio Hondo, in the Pecos, and at Wagon Mound, N.M. The company also purchased a ranch in South Dakota. The daily operations of the Diamond A properties were managed by former Arizona Ranger and U.S. Army Captain, Burton C. Mossman of Roswell, N.M. After 1939, the Diamond A Cattle Company holdings were broken up into smaller parcels and sold. Leon E. Williams, New York businessman, acquired the Wagon Mound and South Dakota ranches. Other parcels were sold to parties in Roswell, New Mexico. By 1977, much of the Diamond A land in New Mexico was owned by Robert O. Anderson, Arco oil tycoon.


4 boxes (3.26 cu. ft.)


The Diamond A Cattle Company collection contains business records of Diamond A Cattle Company ranching operations. Most documents pertain to the period after 1940 during which time Leon E. Williams owned Diamond A ranches in Wagon Mound, New Mexico and Eagle Butte, South Dakota. The records are Williams's business and personal papers.

Related Archival Material

Pioneers Foundation (New Mexico) Oral History Collection Center for Southwest Research, University Libraries, University of New Mexico (Burton Mossman transcripts on reel 3)
Finding Aid of the Diamond A Cattle Company Records, 1878-1956
Processed by Tad McIlwraith
Description rules
Describing Archives: A Content Standard
Language of description
Script of description
Language of description note
Finding aid is in English

Revision Statements

  • June 28, 2004: PUBLIC "-//Un4ersity of New Mexico::Center for Southwest Research//TEXT (US::NmU::MSS 355 BC::Diamond A Cattle Company Records)//EN" "nmu1mss355bc.sgml" converted from EAD 1.0 to 2002 by v1to02.xsl (sy2003-10-15).
  • Monday, 20210524: Attribute normal is missing or blank.

Repository Details

Part of the UNM Center for Southwest Research & Special Collections Repository

University of New Mexico Center for Southwest Research & Special Collections
University Libraries, MSC05 3020
1 University of New Mexico
Albuquerque NM 87131