Address:

U.S. Department of the Interior
Office of Inspector General
1849 C Street NW - Mail Stop 4428
Washington, D.C. 20240

Phone Numbers:

Hotline:
Eastern Regional Office: 703-487-8057 
Central Regional Office: Lakewood, Colorado 303-236-8296
Western Regional Office: Sacramento, California 916-978-5630
Toll Free: 800-424-5081

General Information:
Phone: 202-208-5745  Fax: 202-219-3856