Joseph C. O'Mahoney Federal Center

Joseph C. O'Mahoney Federal Center

General Information

2120 Capitol Avenue
Cheyenne, WY 82001-3633
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Hours of Operation:
7:30 a.m. - 5:30 p.m.
Mon. - Fri., except holidays

Current Tenants:
U.S. District Courts, U.S. Post Office, U.S. Marshal Service, U.S. Attorneys, U.S. Bankruptcy and U.S. Probation

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The Joseph C. O'Mahoney Federal Center is the largest GSA-owned property in the state, and was named after the politician, attorney, and U.S. Senator Joseph Christopher O'Mahoney (1884-1962).

Built in 1964 as a U.S. Post Office/Courthouse of pre-cast reinforced concrete in the Formalist style of the modern era, this building was originally built to provide quality office and work space for the U.S. District Courts and related judicial entities, as well as for the U.S. Post Office and personnel of various other federal agencies. It continues to be used in this way.

The building site covers approximately 1.7 acres. The building has eight floors, a basement and penthouse. It stands approximately 108 feet tall and has three passenger elevators, plus one freight elevator. It provides 156,942 rentable square feet of space for more than 200 federal employees.

Directions & Parking

Parking is available on federal grounds as well as neighboring commercial lots and parking garages.

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Report a Maintenance Issue

For more information on facility repairs, space renovations, or to report a building maintenance issue, please call 307-772-2341 or send an email to the Rocky Mountain Call Center.


  • Vending machines
  • Elevators
  • Underground parking for 81 vehicles

Historic Information

Historic evaluation of the building may occur in 2014.

Art in Architecture Program

For more information on this federal building, please contact David Brackenrich at or 307-261-6425

Last Reviewed: 2020-09-18