Juan José Ríos (Spanish pronunciation: [ˈxwaŋ xoˈse ˈri.os]) is an agricultural city located in Northern Sinaloa, Mexico.

Ejido Las Vacas was founded on 21 September 1938 by presidential decision, by the then President Lázaro Cárdenas del Río.

Between the years of 1946 and 1951 several peasants from Los Mochis, 18 de Marzo and San Miguel Zapotitlán towns, Ahome Municipality; and La Louisiana town, El Fuerte Municipality, requested to the Agricultural Department that they be granted with plots to sow in Ejido Las Vacas.

[5] Several towns in El Fuerte and Choix Municipalities were affected when Miguel Hidalgo Dam construction started.

[7] On 28 February 1955, the 637 peasants who were evacuated from the 11 ejidos, which would be flooded by Fort River when the grout curtain of Miguel Hidalgo dam was closed.

However, locating the 1375 ejidatarios with their families, it needed another presidential decision to locate in 500 ha each ejidatario giving them a 1,600 m2 (40 m x 40 m) plot for living,[7] including as well as streets, schools and other public services, becoming an urban area, which one were named Juan José Ríos,[5] and it became in a sindicatura.

It had a population of 27,938 inhabitants (including both parts of the city − Guasave and Ahome municipalities); in which 13,761 were males and 14,177 were females, according to the 2010 census.