The intriguing nature of Trinity Forest starts with its very conception. Some 50 years back, the location, just south off Highway 12, in the dense underbrush of the Trinity River watershed, an area known as the Trinity Forest, became an illegal dumpsite, mostly of construction debris, stuff like chucks of old concrete, but also trash from locals. As material piled up, somebody would push dirt around to hide it, and subsequent dumping moved to an adjacent spot. Eventually the landfill covered some 150 acres, and grew to a plateau some 15 to 20 feet above the riverbed.