|Slide No. 32||
Bridges: Keystone Wye Bridge
Timber has been and continues to be a viable material for bridge
structures. The Keystone Wye (located outside of Rapid City, SD near Mt. Rushmore) is an
example of a glulam arch bridge. It was built in 1968, and the only maintenance required
because of deterioration during the past 30 years was repair of the concrete deck due to
spalling from de-icing salts.