Based on Clarence E. Mulford's Mesquite Jenkins, Tumbleweed from 1932, Heart of the West addresses the issue of fences on the hitherto free range. Hopalong Cassidy (William Boyd) and Johnny Nelson (James Ellison) have been hired to head a cattle drive by Trumbull (Sidney Blackmer), but then learn that their would-be employer is waging a war against young rancher Jim Jordan (Charles Martin). The latter is erecting fences on his part of the range in order to keep his cattle pure. At first, Hoppy is less than willing to accept Jim's offer of a job, but he agrees once it becomes clear that Trumbull has been using Jim's Black Valley as a safe conduit for cattle rustlings. Heart of the West, which came complete with a title song by Sam Coslow and Victor Young, was partially filmed along California's Kern River.