Claro is a Spanish term meaning clear, light or bright. Bright certainly describes the wood since it exhibits such an assortment of colors: from reds to golds, mixed with tans, grays, black, and brown. Large stands of mature Claro walnut trees were first discovered growing in the following three locations in northern California: 

• The valley of Walnut Creek in Contra Costa County.
• The banks of the Sacramento River, particularly at Walnut Grove. 
• The Wooden Valley east of Napa. 

     It was from these original groves in the late 1800's the famous pioneer John Bidwell began propagating California Claro Walnut at his Rancho Chico Nursery in Chico California.