The dam/spillway below the trout hatchery complex in Roaring River State Park bears the inscription of Company 1713 in stone, but actually predates the Civilian Conservation Corps. In 1865, William McClure constructed a stone and earth dam impounding the waters that gushed from the underground spring to form Roaring River. Two openings left in the mill pond wall became mill races were spillways that exist today in their original locations, forming attractive waterfalls. McClure's Mill, erected below the dam on the site of the present park Lodge, became a social center for the surrounding communities. Sometime around 1920 the mill either burned or was torn down. The original dam spillways were of dry stone construction, without mortar. In 1933, CCC Company 1713 reconstructed the dam using concrete, stone, and mortar with the facings of rough coursed ashlar. The bridge in Spillway, retaining a rustic appearance similar to that of the original dam and mill races, are notable features of the present-day trout park.
The dam/spillway at Roaring River State Park is significant as an early construction project of the Civilian Conservation Corps and also as an example of modern park structure intentionally constructed to resemble a handbuilt rustic structure of a much earlier date. Originally built to create power for a mill, the dam in Spillway were re-created as impounding structures for an important fish hatchery complex. The CCC help to develop this hatchery, which is still in operation under the supervision of the Missouri Department of Conservation.
The dam is still used to impound water for the fish hatchery and the pool below the dam is a very popular trout fishing location.
The dam and spillway were added to the National Register of Historic Places in 1985.