[1] The municipality's Pacific coast serves as a critical nesting area for the leatherback turtle and is protected as the Ramsar site Playa Tortuguera Tierra Colorada.

[6] In the late 16th century, Spanish cattle ranchers brought free and enslaved blacks and mulattoes to the area, from whom most of San Nicolás's present-day inhabitants are descended.

[7] In 2004, inhabitants of San Nicolás and nearby communities began an initiative to separate from Cuajinicuilapa and form a new municipality, citing a lack of resources for development in their area.

[8] On 31 August 2021 the Guerrero state legislature approved the formation of the municipality of San Nicolás comprising ten localities previously belonging to Cuajinicuilapa.

[7] The economy of San Nicolás is based on smallholder farming: farmers grow corn for their own consumption, and sesame and fruit (e.g., mango, papaya and watermelon) for sale to regional markets.