Lying within the Tulum Valley (es:Valle del Tulúm) agricultural oasis, almost 80% of the department's area is cultivated; it is known in particular for its production of wine and its fruit and vegetable crops.

The earliest inhabitants of the area were the Huarpes, who lived by agriculture, hunting, and fishing in the San Juan River.

As part of a reorganisation within the province in 1913, a municipality of Nueve de Julio was created, which took in the localities of Las Chacritas and Rincón Cercado.

The flora is characterized by xerophytic vegetation, such as the jarilla bush and the retamos, although the totora and other types of reed are also found.

Nueve de Julio is among the least populous of the departments in San Juan province, with only 9,307 inhabitants (2010 Census of Argentina).

Las Chacritas, the second most populated locality, attracts residents by its proximity to a main route between San Juan city and Buenos Aires.