Pittsburg is a ghost town in Colfax County, New Mexico, United States. In 1922 Ray Pittman and his brother Russell Pittman constructed and became proprietors of a grocery store located six miles northwest of Gladstone. During 1924 a Post Office was established in the community and was located in Ray Pittman's store thus becoming known as Pittsburg, New Mexico. The Post Mistress was Bernice Martin Pittman, wife of Ray Pittman. The Post Office remained in the building, until 1932 at which time it was closed. Pittsburg is no longer in existence; only a small pile of rubble remains where the store once stood.