Daily Alta California, Volume 1, Number 103, 29 April 1850
REPORT FROM THE SELECT COMMITTEE
On the Derivation and Definition
of the Names of the several Counties
of the State of California, &c.
CONTRA COSTA. — This name signifies “opposite coast,” and the County is so called from its situation opposite San Francisco, in an easterly direction. It is, undoubtedly, one of the most fertile counties in the State, possessing rich agricultural lands, which embrace an interior coast of thirty leagues, extending in the bays of Santa Clara, San Francisco, and San Pueblo, the straits of Carqulnes, the bay of Suisun, and the San Joaquin river; a circumstance which, united to its mild climate, will render it very important. The Pueblo of Martinez is its chief town, and “New York of the Pacific,” as well as other towns on the shores of the San Pablo and San Joaquin, will also very soon effectually contribute to its importance.
“Mount Diablo,” which occupies a conspicuous place in modern maps, is the centre of this County. It was intended so to call the County, but both branches of the Legislature after warm debates on the subject (the representatives of the County opposing the proposed name,) resolved upon the less profane name of ” Contra Costa.”
The following is the history of “Mount Diablo” (Mount Devil ) In 1806 a military expedition from San Francisco marched against the tribe ” Bolgones,” who were encamped at the foot of the Mount; the Indians were prepared to receive the expedition, and a hot engagement ensued in the large hollow fronting the western side of the Mount. As the victory was about to be decided in favor of the Indians, an unknown personage, decorated with the most extraordinary plumage, and making divers movements, suddenly appeared near the combatants. The Indians were victorious, and the incognito (Puy) departed toward the Mount. The defeated soldiers, on ascertaining that the spirit went through the same ceremony daily and at all hours, named the mount “Diablo” in allusion to its mysterious inhabitant, that continued thus to make his strange appearance, until the tribe was subdued by the troops in command of Lieut. Gabriel Moraga, in a second campaign of the same year. In the aboriginal tongue “Puy” signifies Evil Spirit ; in Spanish it means Diablo, and doubtless it signifies Devil in the Anglo-American language.