The municipality of Sain Alto is located at an elevation between 1,900 and 3,000 metres (6,200–9,800 ft) on the Mexican Plateau in northwestern Zacatecas.

It borders the municipalities of Río Grande to the north, Fresnillo to the south, and Sombrerete to the west.

[4] The name of the municipality derives from the spanish word Saín,[10] a group of Zacateco people who established the settlement of Sain Alto sometime around 1535–1540.

[5] The municipal government of Saín Alto comprises a president, a councillor (Spanish: síndico), and thirteen trustees (regidores), eight elected by relative majority and five by proportional representation.

[12] In the 2020 Mexican Census, the municipality of Sain Alto recorded a population of 21,844 inhabitants living in 5504 households.