1st federal electoral district of Sonora

Under the 2023 districting plan adopted by the National Electoral Institute (INE), which is to be used for the 2024, 2027 and 2030 federal elections,^[6] the first district comprises 176 electoral precincts (secciones electorales) across 11 municipalities in the state's north-west:^[7]

• Altar, Atil, Caborca, Oquitoa, Pitiquito, Plutarco Elías Calles, Puerto Peñasco, San Luis Río Colorado, Sáric, Trincheras and Tubutama.

The head town (cabecera distrital), where results from individual polling stations are gathered together and tallied, is the city of San Luis Río Colorado. The district reported a population of 389,127 in the 2020 Census.^[1]

2017–2022

Between 2017 and 2022, the district had the same configuration as in the 2023 scheme.^[10][11]

2005–2017

Under the 2005 plan, the district covered 13 municipalities: the 2023's scheme's 11, plus Benjamín Hill and Santa Ana.^[12][13]

1996–2005

Under the 1996 districting plan, the head town was at San Luis Río Colorado and the district covered the state's north-west.^[14][13]

1978–1996

The districting scheme in force from 1978 to 1996 was the result of the 1977 electoral reforms, which increased the number of single-member seats in the Chamber of Deputies from 196 to 300. Under that plan, Sonora's seat allocation rose from four to seven.^[8] The 1st district had its head town at Magdalena de Kino and it covered 34 municipalities in the north of the state.^[15]