I-29 Sioux City Gateway "Prairie Bridge"
Sioux City, Iowa, is nestled among Missouri River bluffs at the edge of the great prairie stretching westward into Nebraska and South Dakota. It is also situated along the iconic Lewis and Clark Trail. In fact, the only expedition member to perish during the historic journey is buried in the hills of Sergeant Bluff, just south of Sioux City. It was from this vantage point that Lewis and Clark caught their first glimpse of the vast grandeur of the prairie laid before them. The power of this storied landscape can still be felt today in the Sioux City area.
Sioux City has also earned itself a nickname – “Little Chicago” – for its examples of Prairie School styled architecture, which has its roots in the Chicago area and is best represented in the Midwest.
These regional characteristics had a strong influence on the styling of the Prairie Bridge. The design responds to its context with bold Prairie School horizontality, but with very simple details and no appreciable effect on the structural requirements of the bridge.
Long sleek lines are created from different color finishes and articulated concrete surfaces. Colors mirror the warm tans and sandy yellows seen in the local bluffs flanking the river basin.
Anchoring the bridge landings are carefully proportioned concrete planters integrated into the abutments. These are filled with tall prairie and ornamental grasses, in keeping with the structure’s theme. A dramatic cantilevered “shelf” feature is used at the planters, parapet and even at the pier — lending the project a unique flair and stylistic consistency from end to end.
The new bridge is responsive to its geographic and architectural context, and is anticipated to live up to its billing as the new “Sioux City Gateway.”