To create a concrete arch bridge over a river gorge without disturbing the canyon walls or floor below, engineers combined a segmental construction scheme with cable-stay technology. The Crooked River has carved a deep, dramatic gorge into the basalt plains of central Oregon. For generations this 300 ft (91 m) chasm has posed a major obstacle to travel between eastern Oregon and population centers in the northwest of the state; throughout the 1800s, crossing the gorge required a steep descent on the narrow canyon road to a wooden bridge that was often impassable because of flooding.
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