The West Plum Bush Creek Bridge is a historic concrete rigid frame bridge in Washington County that carries US 36 across West Plum Bush Creek near Last Chance. Built in 1938, the bridge is one of a small group of rural concrete rigid frame bridges constructed by the Colorado Highway Department during the late 1930s. It was listed in the National Register of Historic Places in 2002 as part of the Highway Bridges in Colorado Multiple Property Submission.
The bridge is significant for its association with the development of US 36, an important east-west highway route connecting Denver and Colorado’s eastern plains with communities in Kansas and the Midwest. Before US 36 was fully improved, this corridor had roots in earlier state highway development and in the broader network of east-west transcontinental routes that crossed the plains during the early automobile era. By the mid-1930s, the Colorado Highway Department undertook major improvements to the road, upgrading portions of the route from a dirt road to a graded highway.
The West Plum Bush Creek Bridge was built as part of those highway improvements near Last Chance. The small eastern plains community developed in the 1920s after local entrepreneurs Essa Harbert and Archie Chapman opened a gas station along the road, advertising it as the “last chance” to buy gas for some distance. As automobile tourism and commercial traffic increased across the plains, improved roads and bridges became essential to the reliability of the route.
The bridge is also significant for its engineering. A concrete rigid frame bridge differs from a conventional simple-span bridge because the deck and abutments are tied together as a single structural unit. Instead of resting on separate supports, the bridge’s superstructure and substructure work together through rigid concrete connections. This design allowed bridges to carry heavy loads while offering flexibility in span length and skew. Although rigid frame bridges were used in some urban settings, they were never especially common in rural Colorado.
The West Plum Bush Creek Bridge is a well-preserved example of this bridge type. Its character-defining features include its single-span concrete rigid frame superstructure, concrete abutments and wingwalls, concrete deck with asphalt overlay, and Colorado Department of Highways standard slotted concrete guardrails. The bridge is 72 feet long, with a 58-foot main span, and retains the understated, practical appearance associated with Colorado Highway Department design in the 1930s.
The bridge’s setting also contributes to its significance. Located in open high plains grasslands west of Last Chance, the West Plum Bush Creek Bridge reflects the rural transportation landscape of eastern Colorado. Its modest scale should not obscure its importance. Many historic bridges are significant not because they are monumental, but because they represent once-common design solutions that have become increasingly rare as highways have been widened, realigned, or reconstructed.
As part of the Historic Bridges of Colorado preservation effort, the West Plum Bush Creek Bridge has been identified as a preservation-priority bridge. Its long-term preservation offers an opportunity to retain a rare rural example of concrete rigid frame construction and to interpret the role of US 36 in connecting the Front Range, eastern Colorado, and the central plains.
The West Plum Bush Creek Bridge helps tell the story of Colorado’s highway modernization during the 1930s, when improved roads and more durable bridges reshaped travel across the state. Preserving the bridge allows this important plains transportation corridor to remain connected to its historic infrastructure and engineering heritage.
This bridge is one of the 23 preservation-priority bridges featured in Colorado Preservation, Inc.’s Historic Bridges of Colorado listing. View the full Historic Bridges of Colorado overview to learn more about the statewide preservation effort.