Border Field State Park is in the extreme southwest corner of the continental United States. It is a 418 acre parcel which is part of the 278 unit California State Park.
The Treaty of Guadalupe Hidalgo was concluded on February 2, 1848, officially ending the war with Mexico. It provided that the new international border between the two countries be established by a United States and Mexican Boundary Commission. Both commissions surveyed and located the initial borderline at Border Field.