He notably commissioned the first land survey of San Francisco to Jean Jacques Vioget in 1839.

In 1837, de Haro bought the Rancho Laguna de la Merced, which included Lake Merced and portions of northern San Mateo County, from the grantee José Antonio Galindo.

And in strange turn of events, in 1838, Alcalde de Haro issued an arrest warrant for Jose Antonio Galindo for the murder of José Doroteo Peralta (1810–1838).

[5][6] De Haro died on 28 November 1849 and is buried at the Mission Dolores cemetery in San Francisco.

[7] De Haro Street, in the Potrero Hill neighborhood of San Francisco, is named after him.