Rancho Chico, a vast expanse covering 26,000 acres, was purchased in 1849-50 by John Bidwell. In 1865 he began construction of the nearby mansion, which in time became the social and cultural center of the upper Sacramento Valley. Through his advancement of agriculture, however, Bidwell made his greatest contribution, as the introduction here of plants from all over the world opened the door to California’s present agricultural treasure house.