<P>Jerry Taylor and Ray Poteat take readers on a mile-by-mile trip through the tunnels and over the bridges of the historic CSX Clinchfield. Completed in 1915, the Clinchfield Railroad follows a scenic route through rugged mountain country in the eastern United States. Facing the challenge of this difficult terrain, engineers and more than 3,000 laborers built the railroad using construction standards unheard of at the time. The results were so durable and forward looking that for nearly a century there has been no need to enlarge its tunnels or strengthen its bridges. Though the Clinchfield is not well known outside its territory, its history and challenging construction have been continuing sources of fascination for rail fans.</P>