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D. M. Riordan Papers,

Identifier: MSS-169-BC

Scope and Content

The records contain correspondence relating to Riordan's Flagstaff businesses, including the Arizona Lumber Company. There are several typed and handwritten letters reflecting management of the Arizona Mineral Belt Railroad in Flagstaff, Arizona, from 1886-1888. These letters discuss Riordan's personal and lumber contracts with the railroad, arrangements with a merchant in Las Vegas, New Mexico, and discussions with Ayer about the lumber mill. A second group of letters between Riordan, family members, and friends relates stories of Riordan's travels between 1900 and 1907, after Riordan left Flagstaff for New York City. Some letters discuss Riordan's mining exploration work at this time and others were written to Riordan by acquaintances. Included in this letter book is Treasury Agent Riordan's business card, issued at the time of his participation in the American Relief Expedition to Europe in 1914.

The letter books contain drafts of two interesting documents. First, a typed report of living conditions at the Fort Defiance Reservation is included; a few pages at the beginning of this document are missing. Second, a manuscript entitled 'The Great Healing Ceremonies of the Hoh-Kawn Dance of the Navajo Indians' describes in detail a traditional Navajo ceremony. Presumably, both of these documents date to 1882-1884, the time during which Riordan was the Navajo Indian Agent at Fort Defiance, Arizona.


  • 1886-1914

Language of Materials


Access Restrictions

The collection is open for research.

Copy Restrictions

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

Biographical Information

Denis Mathew Riordan, Indian Agent, lumberman, railroader, and philanthropist, was born in Troy, New York, in 1848. After brief participation in the Civil War, Riordan moved west, working in resource related industries in the Arizona, Wyoming, and Utah Territories from 1868-1882. Specifically, his work related to railroading, mining, and lumber milling. He made some money investing in an Arizona copper mine and was successful with other small stock ventures. In 1882, Riordan was hired as the Indian Agent on the Navajo Fort Defiance reservation.

In 1884, Riordan was enticed by a generous salary offer from Chicago merchant, philanthropist, and Field Museum and Newberry Library benefactor, Edward E. Ayer to run a saw mill in Flagstaff, Arizona. Ayer sold Riordan the mill in 1887 for $145,000 (the equivalent of $2.2 million in 1992.) After the mill purchase, the name changed from the Ayer Lumber Company to the Arizona Lumber Company. In 1891, the name changed again to the Arizona Lumber and Timber Company. The mill was highly successful and spawned Riordan's involvement in other local businesses. Riordan and other Flagstaff investors acquired the financially troubled Arizona Mineral Belt Railroad Company in 1888. It had been conceived as a freight line from Flagstaff to the business and mining center of Globe, in south-central Arizona. Riordan used the line to haul timber from the area southwest of Flagstaff to his mills. In 1897, he sold the company to his brothers, Timothy and Michael, who had helped run the business.

Riordan was involved in civic and philanthropic ventures during his residence in Flagstaff. He created a firefighting company called the D.M. Riordan Hose Company. With his wife, Celine, Riordan fostered education and science in the community. Riordan's civic contributions also included participation in local government.

In 1897, Riordan left Flagstaff for New York City and, later, San Francisco. His activities at this time included travel, mining exploration, and a position as mining consultant for the General Electric Company. In 1914, he accepted a request from Woodrow Wilson's administration to travel to France and rescue Americans stranded in Europe at the beginning of World War I. Named a special treasury agent for the project, known as The American Relief Expedition, Riordan was entrusted with $1.5 million in federal funds plus $3 million from private sources to complete the task.

Riordan died at his San Francisco home in 1928.


1 box (.35 cu. ft.) + 1 volume


The Riordan records include business and personal correspondence relating to Denis Mathew 'Matt' Riordan's milling and railroading businesses at Flagstaff, Arizona, in the 1880s. Additional correspondence reflects Riordan's family and personal relationships after he left Flagstaff in 1897. Some material relates to Riordan's position as the Fort Defiance Indian Agent (Navajo) from 1882-1884.

Relevant Secondary Sources

  • Cline, Platt. They Came to the Mountain: The Story of Flagstaff's Beginnings.Flagstaff: University of Northern Arizona/Northland Press, 1976.
  • Cline, Platt. Mountain Town: Flagstaff's First Century.Flagstaff: Northland Publishing, 1994.
Finding Aid of the D. M. Riordan Papers, 1886-1914
Processed by Tad McIlwraith
Language of description
Script of description
Language of description note
Finding aid is in English

Revision Statements

  • June 28, 2004: PUBLIC "-//University of New Mexico::Center for Southwest Research//TEXT (US::NmU::MSS 169 BC::D. M. Riordan Papers)//EN" "nmu1mss169bc.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