The Valley of the Giants is set on the edge of Humboldt Bay in the fictional town of Sequoia, California. Starting in 1850s, with John Cardigan founding the logging company to build a life for him and his son Bryce, the novel follows the ups and downs of the Cardigan family and the on-going rivalry with Colonel Pennington over logging rights and other business matters. When Bryce Cardigan returns home from the college he finds out that his father's company is in trouble and that Pennington is pushing them out of business. He must try to save the company and screw Colonel Pennington, while juggling a secret relationship with Shirley, Pennington's niece.