Great Smoky Mountains National Park managers are advising recreational users of the 9-mile unopened portion of the Foothills Parkway east of Walland,Tenn. to watch out for vehicles from November 12 through December 22. The section is popular with hikers, cyclists and horseback riders who have had the unopened gravel road to themselves. During the next six weeks these users can expect to encounter construction vehicles each Monday through Friday while a Park contractor does some core drilling at the far eastern end of the roadway.