Spanning Time: America's Covered Bridges explores the cultural significance, history, construction techniques, preservation efforts and tourist activities surrounding covered bridges throughout the United States. These structures offer a focal point for civic pride and, in many cases, provide a centerpiece for local tourism in their respective communities. Actor-songwriter Tim Grimm guides you through this educational, entertaining and often whimsical look at covered bridges as a direct connection to the past, an elegant solution to a 19th-century transportation problem and the basis for a modern tourist industry. Spanning Time includes scenic images of covered bridges in rural and small town settings in Indiana, Ohio, Oregon, New Hampshire, New York, Pennsylvania and Vermont. It also visits covered bridge festivals in Oregon, Indiana and western Pennsylvania, to explore the modern tourist industry built around these historic structures.

Sunday, 5/4/08 from 4-5 a.m. ET