"The trail surface varies from asphalt to chip seal to limestome gravel. From Alton to the Lewis and Clark State Memorial, the trail is mostly asphalt. South of there, the trail rides on a levee along the Chain of Rocks Canal which is where most of the gravel and chip seal stretches are. Between the Lewis and Clark Memorial and ILL 143, there are some very tight anti-car barriers that may violate the Americans with Disabilities Act. They are at driveway crossings with truck traffic. "