The Hamburg Trail is an eight-mile hiking and biking trail linking the Katy Trail to the August A. Busch Memorial Conservation Area Headquarters. It was created through a cooperative effort of the Missouri Department of Conservation, the Missouri Department of Natural Resources, and the United States Department of Energy during the Weldon Spring Site Remedial Action Project, which carried out the environmental cleanup of former explosives production and uranium processing facilities in this part of St. Charles County. The trail passes through the woodlands and prairies of the Weldon Spring Conservation Area, the August A. Busch Memorial Conservation Area, and the Weldon Spring Site, while also connecting the history of local communities including Howell, Hamburg, and Toonerville. Burgermeister Spring lies within a 640-acre tract that began as a Spanish Land Grant awarded in 1798 by Spanish Lieutenant Governor Don Zenon Trudeau to Alexander Andrews, who sold it in 1800 to Francis Howell, Sr. The land remained in the Howell family for several generations until its sale in 1870 to Mathias and Johanna Burgermeister, and it stayed in the Burgermeister family until 1940, when the U.S. government displaced residents to build an explosives production plant for the war effort. Today the spring is part of the U.S. Department of Energy's long-term monitoring plan for the Weldon Spring Site, and dye tracing studies in the 1990s showed a hydraulic connection between groundwater at the site and the spring. From 1941 to 1945, during World War II, the U.S. Army produced explosives at the 17,232-acre Weldon Spring Ordnance Works near Weldon Spring, Missouri. After the war, portions of the land were transferred to the State of Missouri for the August A. Busch Memorial Conservation Area, to the University of Missouri for agricultural use, and to St. Charles County and the Francis Howell School District, while the Army retained the rest as a training area. About 15,000 acres of the original facility are now owned by the Missouri Department of Conservation as the August A. Busch Memorial and Weldon Spring Conservation Areas. In 1955, the Army transferred about 200 acres to the Atomic Energy Commission for construction of the Weldon Spring Uranium Feed Materials Plant, which processed uranium ore concentrates and a small amount of thorium from 1957 to 1966. Because hazardous waste remained on the site, the Department of Energy established the Weldon Spring Site Remedial Action Project in 1986. Surface remediation ended with the construction of a 45-acre disposal cell, completed in 2001, that serves as a repository for 1.48 million cubic yards of radioactively and chemically contaminated waste and provides long-term isolation and management of those materials.
