D&RGW(U) iron trestle?

The D&RGW(U) alignment of 1883-1890 crossed the Utah/Colorado state line about 1.9 miles north of old highway U.S. 40, where the surviving railroad grade is easily discerned in Google Maps satellite view. About 1400' east of the border, the railroad crossed a large arroyo on a most unusual pile trestle, one with piles consisting of 36" diameter segmented cast iron tubes filled with concrete. The attached photos give a fair idea of what remains. Close examination with Google Map's satellite view suggests that there are about a dozen such piles exposed here, as bents of three. I suspect that most of the iron shells standing above ground were salvaged, not long after this route was abandoned circa 1890, so that what I show was then underground and was exposed by later erosion.

I had not previously found anything quite like this in railroad bridge work, and thought that 1883-90 is a bit late for such use of cast iron. Can anyone provide further information?

A typical pile, 36" diameter.



Group of piles exposed along the active channel. There are more hidden in the brush. Note the timber piles exposed to the left.


Overall view from the head of the SE approach fill. Note the three piles that are barely exposed about 1/3 the way up the NE approach fill.


Remains of full 3-pile bent, with some timber piles near top of fill.