Bartolomé Ferrelo was born in Bilbao, Spain. He became a skilled mariner and navigator, and in 1542, he served as a pilot in Juan Rodríguez Cabrillo's voyage northward along the Pacific coast of Mexico and California. The expedition planned to search for the fabled Strait of Anian, which it was thought would provide a seaward route through North America from the Pacific Ocean to the Atlantic Ocean.
Cabrillo's two ships embarked from Navidad, near Manzanillo, Mexico, on June 27, 1542, in an expedition that had been organized by Mexican governor Antonio de Mendoza. In early January 1543, Ferrelo assumed command of the expedition following Cabrillo's death on an island in the Santa Barbara Channel. He continued the search for the Strait of Anian, reaching as far as Cape Blanco on the Pacific coast of Oregon, which he sighted and named. Problems with the ships, food shortages, and severe weather led Ferrelo to end his explorations and head back to Mexico. While sailing southward along the coast of what is now northern California, he sighted a strip of land, which he named Cape Mendocino in honor of Mendoza. Ferrelo and the expedition arrived back at Navidad, Mexico, on April 14, 1543.
The eleven-month cruise, begun by Cabrillo and completed by Bartolomé Ferrelo, demonstrated to Spanish geographers and navigators that the coastline from Mexico to California was unbroken. Although Ferrelo brought no news about the Strait of Anian, he had gone farther north along the Pacific coast of North America than any other European had up to that time, making the first recorded sighting of the Oregon coast.