European settlement of Refugio Valley first, briefly, was for agriculture. From 1878 the main production facilities of California Powder Works occupied the lower Refugio Valley; to the southeast in the upper Valley were small storage and shipping facilities.
When the era of explosives manufacture ended, the upper Valley was subdivided and sold as residential lots beginning in 1972.
Later, beginning in 2001, residential development occured in the lower Refugio Valley as economic values and new construction techniques overcame geologic and hydrologic challenges.