John S. McCain III
National Center for Environmental Conflict Resolution

Project Case Summary

MCAS Yuma-Yuma County Airfield Access Mediation

Location: Arizona


The County of Yuma, Arizona, and the United States Department of the Navy sought the services of the U.S. Institute for Environmental Conflict Resolution to mediate a dispute over the value of a 129-acre parcel owned by the County adjacent to the Marine Corps Air Station Yuma (MCAS). The Navy sought to incorporate the parcel into the air station but could not agree with the County on a price for the parcel. No lawsuit was pending, but the Navy had signaled that it would file a lawsuit if the parties were unable to reach an agreement on a selling price.

MCAS is the busiest air station in the Marine Corps and the third busiest in the Naval service. It is also one of the largest single contributors to the economy of Yuma County. MCAS shares an airfield with the Yuma International Airport, a commercial service airport owned by the County of Yuma and operated by the Yuma County Airport Authority. The U.S. Institute, in conjunction with the parties, engaged Joe McMahon of Joseph P. McMahon, Jr., LLC as the mediator for the dispute.


The parties worked through the complex land valuation issues with the mediator and came to a "win-win" resolution that achieved their primary goal. In the process, they also enhanced their ongoing working relationship. When they reached an agreement, they agreed that the benefits and impacts of the agreement reached resulted in "better relations among community and military" and "from the government perspective, improved mission capability."

Results and Accomplishments

The Mediator worked closely with the parties to:

  • Clarify the parties' choices;
  • Improve communications and the exchange of needed information;
  • Develop and study options for resolution not only of the dispute but other elements of their relationship that could be effectively addressed in the mediation;
  • Encourage open dialogue and a broad approach to both resolving the dispute and improving the parties' working relationship; and
  • Achieve a successful resolution to the dispute.


Partner from National Roster of ECR Practitioners
Joe McMahon of Joseph P. McMahon, Jr., LLC

U.S. Institute Project Lead
Cherie Shanteau-Wheeler,
Senior Mediator/Senior Program Manager
Litigation and Administrative Appeals and Training Programs
Phone: (520) 901-8546; FAX: (520) 901-8547 Email: Website:

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