The Vaquita is known to occur only in the northern Gulf of California, Mexico, mainly north of 30º45'N and west of 114º20'W (Gerrodette et al. 1995). The so-called "core area" of its range consists of about 2,500 km² centred between Rocas Consag, and the town of San Felipe, Baja California. This core area straddles the southern boundary of the Upper Gulf of California and California River Delta Biosphere Reserve. There is no evidence to indicate that the vaquita's overall range has changed since prehistoric times.  Most vaquita detections are now made in a 12 x 25 km area called the Zero Tolerance Area (ZTA), where all fishing activity and navigation has been legally prohibited since 2020.

The species is endemic to the upper quarter of the Gulf of California, its extent of occurrence is >2,000 km² and until recently its area of occupancy (core area) was considered to be approx. 2,500 km².  Since 2018, however, nearly all visual and acoustic detections have been inside the ZTA, suggesting that the area of occupancy (AOO) is actually closer to around only 300 km².

An International Committee for the Recovery of the Vaquita (CIRVA) was established in 1997 and has developed many recommendations over its 11 CIRVA reports (all available at iucn-csg.org). The most consistent and important recommendation is to permanently ban the manufacture, possession or use of all gillnets on land or sea throughout the range of Vaquitas. In June 2017 a permanent ban was published in Mexican regulations that made the use or transport of gillnets illegal, with exemptions for fishing of two fish species (curvina (Cynoscion othonopterus) and sierra (Scomberomorus sierra; and S. concolor).  Night fishing was banned and legal entry and exit points were restricted.

CIRVA recommended that as many Vaquitas as possible be captured and moved into a sanctuary as quickly as possible, but the capture and protection effort in 2017 failed (Rojas-Bracho et al. 2019). 

From September 2020 to April 2021, Mexico enacted a series of new regulations.

In September 2020 an Agreement was published in the Federal Register a Gillnet Exclusion Zone (GEZ) that established:

• a 225 km² Zero Tolerance Area (ZTA) with no fishing or entry allowed and with year-round 24-hour enforcement through maritime, air and satellite patrols and surveillance;
• a ban on the possession, manufacture, sale, transportation gillnets in and around GEZ;
• a set of restrictions banning fishing at night, specifying landing sites, reporting of bycatch and lost gear, and requiring mandatory vessel monitoring systems for all pangas (small fishing vessels);
• removing of illegal and ghost nets; and
  
• surrendering of all gillnets by fishers within 60 calendar days of the date of publication of the Agreement.

In January 2021 new regulations were published to:  create the Intergovernmental Group on Sustainability in the Upper Gulf of California (GIS) to analyse, define, coordinate, monitor and evaluate actions and strategies related to compliance with the implementation of this agreement under Secretary of Environment (SEMARNAT), The National Commission of Fisheries and Aquaculture (CONAPESCA) and the Navy (SEMAR).  In July 2021 an agreement was published to define ‘trigger factors’ that allows some gillnetting within the ZTA until certain conditions are met.  Despite these and numerous other protective measures, gillnetting remains the primary fishing gear used even in the area inhabited by the last few Vaquitas alive (Rojas-Bracho et al

. 2019, 2021).The Vaquita is listed on CITES Appendix I.