Bulging out between cornfields to the west and the town of Wood River to the east is the only remaining roundhouse dome in the world. The Wood River geodesic dome is an all-steel structure built in 1961—with construction overseen by the father of geodesics, R. Buckminster Fuller himself. The dome is constructed from 1,000 hexagonal steel panels each 15 feet in width, has a diameter of 354 feet, and is 120 feet tall (tall enough to be required to display aircraft lights). Its sequence of construction was quite novel: it was built from the top down. Using a massive inflatable nylon bag, the first 220 panels were welded together on scaffolding, after which the nylon bag was inserted under these panels and inflated to lift the dome structure so that additional panels could be added at ground level. Rising in 26 lifts, by the time the last row of panels was welded in place at the ground level the pneumatic bag held all 560 tons of steel on 1.6 ounces of air per square inch.
This is one of two domes whose construction Fuller oversaw for the Union Tank Car Company The second dome, larger than this, was built near Baton Rouge, Louisiana, in 1958, but was demolished in 2007. The Wood River dome can easily house a football field, and as a regional railcar repair plant the dome itself covers 37 work tracks and a turntable to place the cars on the tracks. The dome has gone through numerous owners since Union Tank Car sold it in 1975, and has been owned by Watco since 2007. As the largest short line railroad company in the United States, Watco Transportation Services owns and operates dozens of tracks across the United States and Canada. By buying up smaller track, Watco makes its business through providing not trunk line arteries but myriad secondary lines that feed into this system.