It replaced the Baja California Province (1773–1824) of the Spanish colonial Viceroyalty of New Spain, after Mexican independence.

[1][2] Baja California's northern border with Alta California was first established to demarcate areas of Franciscan and Dominican missionary authority, precisely set on August 19, 1773, near San Juan Bautista Creek by Fray Francisco Palóu.

[3] In 1848, under the Treaty of Guadalupe Hidalgo, this international border was shifted further north to San Diego Bay, adjusting it to the claim of Juan Rodríguez Cabrillo and the "sea-to-sea" claims of Sir Francis Drake and of the former colony of South Carolina.

[4][5] Translated into English, the inscription on the marker reads: San Juan Bautista Creek: Juan Crespí, May 1 for the setting of the first international division line between Old or Lower California (Dominicans) and New or Upper California (Franciscans) five leagues to the north (Valley of the Médanos) being established by: Priest Francisco Palóu on 19 August 1773 (Mojonera of Palou) in compliance with the instructions put forth on the April 7, 1772 Concordato.Rosarito Historical Society, Baja California A.C. at The Mission, Baja California, on 20 May 1990.

Monument donation: Mario Reyes Coronado De Villasari & family .