Rainbow Bridge (Brush Creek Bridge)

James Barney Marsh was an Iowa-based civil engineer who founded the Marsh Engineering Company in Des Moines around 1909. Marsh patented his distinctive concrete-and-steel arch bridge design in 1912 — a hybrid construction technique that combined the structural strength of steel reinforcement with the durability and lower cost of mass concrete. The design used steel reinforcing bars embedded within a concrete arch that rose above the deck, with the deck itself hung from the arch via concrete pylons or, in some variants, suspended from the arch with steel rods.

The Marsh Arch design was widely adopted across the central United States during the 1910s and 1920s. The Marsh Engineering Company built dozens of bridges across Iowa, Kansas, Missouri, Oklahoma, Nebraska, and surrounding states; other engineering firms licensed the patent and built additional examples. The design was particularly well-suited to medium-span crossings (60 to 200 feet) where steel truss construction was unnecessarily expensive but conventional concrete arches were less structurally efficient. The distinctive aesthetic — the rising rainbow-shaped arch above a flat deck — was also a selling point in an era when bridge architecture was seen as a public civic statement.

By the 1930s and 1940s, the Marsh Arch design had been largely superseded by newer construction techniques. Most surviving Marsh Arch bridges were replaced by more modern structures across the mid-20th century as highway loads increased and the original concrete began to show its age. A small number of intact Marsh Arch bridges survive nationally, generally on bypassed sections of historic highways or in pedestrian-only conversions like the Brush Creek bridge. The Riverton example is among the most-documented and best-preserved examples of the design.

The Brush Creek bridge was completed in 1923 as part of an upgrade to the existing rural road network across southeast Kansas. The bridge replaced an earlier wooden bridge over Brush Creek and was funded jointly by Cherokee County and state highway sources. Construction took several months and was a substantial event for the small Riverton community; period photographs show locals gathered at the bridge site during construction and at the formal opening ceremony.

When Route 66 was designated in 1926, the new highway was routed across the existing 1923 bridge — one of multiple Marsh Arch bridges that the route used across its southeast Kansas alignment. The bridge carried Route 66 traffic across its full commercial peak from the late 1920s through the mid-20th century, with all the migrant, military, commercial, and tourist traffic that defined the Mother Road's heyday passing over the arch.

By the 1980s, the bridge's narrow deck width and structural age made it inadequate for modern truck traffic. The state realigned Route 66 around the bridge via a new modern crossing slightly to the north, leaving the original Marsh Arch bridge bypassed and at risk of demolition. A local preservation effort beginning in the late 1980s and 1990s — led by Route 66 enthusiasts and Cherokee County residents — successfully argued for the bridge's preservation as a pedestrian-only historic structure. The bridge was added to the National Register of Historic Places in the 1980s and is now formally protected.

The bridge is approached from a short loop off the main Route 66 alignment — roughly two miles southwest of Nelson's Old Riverton Store, on SE 50th Street. Signage is reasonably good though not abundant; most travelers find the bridge by following Route 66 alignment signs or by asking for directions at Nelson's Store. There is a small unpaved parking area at one end of the bridge and an interpretive sign explaining the bridge's history and the Marsh Arch design.

Pedestrians and bicycles can cross the bridge freely. Motor vehicles are no longer permitted on the bridge itself — visitors park at the small lot and walk across or photograph from either bank. The bridge's narrow deck and the arch rising overhead produce a distinctive walking experience that's notably different from any modern bridge. The full crossing takes perhaps two minutes at a slow walking pace, and most travelers walk across in both directions to photograph the structure from multiple angles.

Best photography is from the side angles where the full rainbow profile of the arch is visible against the sky, rather than from the deck itself where the arch is largely above the camera. Morning light from the east and late-afternoon light from the west both produce strong photographs depending on which direction you approach from. Fall is generally the most photogenic season — the surrounding trees turn yellow and orange against the white-gray concrete of the bridge — though spring blooms and summer green also produce strong images. Winter light is flat but the bare trees expose the bridge's structural profile most clearly.

The Rainbow Bridge is essentially always visited as part of a combined sequence with Nelson's Old Riverton Store — the two stops are two miles apart and form a natural pairing. The standard plan: arrive at Nelson's first for shopping and lunch (45-60 minutes), then drive southwest to the bridge for photography and a walk across (15-20 minutes). The combined visit to both Riverton attractions takes about 60 to 90 minutes total.

Within the broader Kansas Route 66 day, the Riverton stops sit in the middle of the corridor between Galena to the north (eight miles) and Baxter Springs to the south (seven miles). Most travelers visit Cars on the Route in Galena first, then move south to Riverton for Nelson's and the bridge, then continue to Baxter Springs for the Heritage Center and lunch or dinner at Cafe on the Route. The full Kansas Route 66 sequence covers all three towns in a relaxed three to four hours.

For travelers continuing east toward Missouri, Joplin is ten miles east of Riverton and is the standard overnight destination for travelers covering this stretch. For travelers continuing west into Oklahoma, Miami is roughly fifteen miles south and is the first major Oklahoma Route 66 town. The Rainbow Bridge is a natural last-photograph stop before crossing one of the state lines.