Don't recall if I brought this topic up before on this forum. I don't see it in the archived discussions. Anyway...
There was a tall iron bridge in Stephens County, Texas called the Canyon Bridge (but with "Canyon" spelled the Spanish way with a tilde). The bridge must have dated from the early years of the T&P. I read somewhere that it was covered with fill. Presumably it's still there only buried.

A November 1916 article in the Fort Worth Star-Telegram relates that the iron bridge was built in 1881. It was second in height (in the Southwest) to the Pecos River High Bridge on the Southern Pacific's Sunset Route. The T&P deemed its bridge too expensive to disassemble so they spent nearly a year dumping gravel and dirt from the bridge to bury it. A concrete arch was constructed in the middle to protect against flood damage.
So this bridge is still there--buried--east of Ranger and west of Strawn.

P.S. Since the Pecos River High Bridge was not built until 1892, then this T&P bridge was the highest in the Southwest for about 11 years!