According to the official website of the National Park Service, the Natchez Trace Parkway boat ramp in Colbert County, Alabama is a concrete ramp with a width of 12 feet. It provides access to the Tennessee River, specifically Pickwick Lake, which is a popular spot for fishing and boating activities.

The website also states that boats of various sizes and types are permitted on Pickwick Lake, including motorized boats, sailboats, and canoes/kayaks. However, there may be restrictions on the use of certain watercraft depending on the season, water levels, and other factors. It is recommended to check with local authorities or the National Park Service before launching any watercraft.

Based on the information available, it appears that the Natchez Trace Parkway boat ramp in Colbert County is a suitable facility for launching boats onto the Tennessee River.