49, Washington County Cotter Tunnel, rail tunnel under US 62, MNA Railroad, northwest of Cotter, Marion County Crest Tunnel, rail tunnel under State Highway 14, MNA Railroad, northwest of Omaha, Boone County Cricket Tunnel, rail tunnel under old U.S. Route 65, MNA Railroad, south of Omaha, Boone County Pyatt Tunnel, rail tunnel under County Road 408, MNA Railroad, southeast of Pyatt, Marion County California Colorado Alpine Tunnel, abandoned rail tunnel, , Denver, South Park and Pacific Railroad, northeast of Pitkin, under the Continental Divide Beavertail Mountain Tunnel, twin tunnels, Interstate 70 and US 6 east of Palisade Busk-Ivanhoe Tunnel, abandoned rail tunnel, Colorado Midland Railway, now part of an aqueduct, under the Continental Divide near Hagerman Pass Eisenhower-Johnson Memorial Tunnel, twin tunnels, Interstate 70 under the Continental Divide near Loveland Pass northeast of Dillon Hagerman Tunnel, abandoned rail tunnel, Colorado Midland Railway, under the Continental Divide near Hagerman Pass Hanging Lake Tunnel, twin tunnels, Interstate 70 and US 6, Glenwood Canyon project, east of Glenwood Springs Mesa Verde National Park Tunnel, main Park road between milesposts 4 and 5, 0.28 miles long Moffat Tunnel, rail tunnel, Union Pacific Railroad (formerly Denver and Salt Lake Railway), under the Continental Divide near Rollins Pass ; also a water tunnel No Name Tunnel, twin tunnels, Interstate 70 and US 6, Glenwood Canyon project, east of Glenwood Springs Reverse Curve Tunnel, westbound Interstate 70 and westbound US 6, Glenwood Canyon project, east of Glenwood Springs Veterans Memorial Tunnels/Twin Tunnel, twin tunnels, Interstate 70 and US 6, east of Idaho Springs Wolf Creek Pass Tunnel, US 160 between South Fork and Pagosa Springs Connecticut Heroes Tunnel, twin tunnels, Wilbur Cross Parkway/State Route 15, West Rock Ridge State Park, in New Haven Pequabuck Tunnel, rail tunnel, originally Hartford, Providence and Fishkill Railroad, Plymouth Pitkin Street Tunnel, road tunnel between Elm and State streets, downtown New Haven Shepaug, Litchfield and Northern Railroad, abandoned rail tunnel in Washington, now a rail trail Taft Tunnel, rail tunnel, Providence and Worcester Railroad (originally part of Norwich and Worcester Railroad), , in Lisbon (oldest active railroad tunnel in the United States) District of Columbia 9th Street Tunnel, under the National Mall (one-way southbound from Constitution Avenue NW to I-395), NW to SW DC 12th Street Tunnel, under the National Mall (one-way northbound from I-395 and Independence Avenue SW to Constitution Avenue NW), SW to NW DC 16th Street NW tunnel, twin