Akodon spegazzinii is found in northwestern Argentina, in the provinces of Salta, Catamarca, Tucumán, La Rioja, and Mendoza, at altitudes of . Although its main distribution is in the northern provinces of Salta, Tucumán, and Catamarca, there are also scattered records from the more southern provinces of La Rioja and Mendoza, where it is likely restricted to patches of wet habitat. "Akodon alterus" has been reported from Jujuy, but this record was likely based on misidentified specimens of "A. boliviensis", and records of "Akodon spegazzinii" from Jujuy were based on misidentified "A. sylvanus". "Akodon spegazzinii" is known from a paleontological site in
Catamarca Province San Francisco pass and mules were bred for the Bolivian market in the 1910s. Mining was important in the past. After becoming less active in the early 1990s, grew to now account for over 20% of the economy. Catamarca is home to one of the largest copper gold mines in the world, Bajo de la Alumbrera, which produces approximately 600,000 ounces of gold and 190,000 tonnes of copper annually. The mine employs over 1,000 people and contributes hundreds of millions of dollars in taxes and royalties to the federal and provincial governments. The agriculture of Catamarca focuses on wood (walnut),