Born in Cognac, France, Covillaud moved to New Orleans, Louisiana, in 1841. He lived there until 1843, when he moved to St. Louis, Missouri, to work in a trading enterprise. In 1846, he joined a party of trappers coming to what would soon become known as Marysville. Hired by Theodor Cordua, he was among the first to mine for gold on the Yuba River in 1848. That same year, Cordua decided he could not operate his ranch alone and took Covillaud in as a partner, selling him half the ranch. Covillaud also married Mary Murphy that year. The following year, in 1849, he persuaded Mary's two sisters' husbands, Michael C. Nye and William McFadden Foster, to buy the other half of the ranch from Cordua. Covillaud soon bought this land from his brothers-in-law and reunited it as a single ranch. Later in 1849, Covillaud sold most of the ranch to José Manuel Ramirez, John Sampson, and Theodore Sicard. He died in 1867 and was buried in the Marysville City Cemetery.