Toothrock Tunnel on Columbia River Highway - Bonneville OR
The US Bureau of Public Roads (BPR) built the Toothrock Tunnel No. 4555 on the Columbia Gorge Highway near Bonneville, Oregon.
Heading east on Interstate-84, as one approaches the Bonneville Dam, vehicles pass through an 837-foot, semicircular bore into Tooth Rock. Today, Toothrock Tunnel's artful design of basalt rockwork and concrete construction can be appreciated for its rustic, historic appearance as well as its 'natural' fit with the mountainous characteristics of the area.
When plans were unveiled for it in 1935, however, it represented major improvements in modern highway design with its "skewed arch portals" fitting topographic conditions and a state-or-the-art lighting...