Since the early frontier days, Tehama has developed a strong agricultural and lumber economy. Most of the farm acreage is rolling terrain used for cattle grazing. In recent years, significant amounts of land have been converted from range and field crops to higher value orchards. Field crop acreage in alfalfa, wheat, rice, and corn has shifted to walnut, almond, prune, and olive orchards. The county has 1,381 farms and farm-related jobs account for 14 percent of total employment.
Walnuts are the county's top commodities.
While valuing its agricultural heritage, the county is changing and is actively seeking new diversified industry to provide employment opportunities for its citizens. There are 24 manufacturing plants in the county, which provide about 20 percent of total employment, considerably higher than the percentage of manufacturing jobs in the state. While the companies make everything from electronics to plastic products, the leading classes of products are lumber and pulp, followed by food products.