BNSF/GN 1913 Trestle over Teton River near Collins, MT

(Bridge Hunter; a photo with a train on it; Satellite)

The satellite image is a text book example of how a meandering river can cut a valley that is more like a trench. That is, it has steep sides. I'm also reminded how spoiled I am by the street view car in the Midwest states. A street view car has not been on the road next to the bridge. A road can afford the grades necessary to go down into the flood plain and then back out. The railroad can't afford those grades. Thus it bridges over the entire "trench."

Andrew Tuttle posted two photos:

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As with most steel tower trestles, the span across the tower is shorter than the span between towers. But this trestle is unusual because the depth of the girders for the short spans are as deep as those for the long spans.

Andrew Tuttle posted five photos.

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1902 eBook1, p267

Photo from Railroads of Montana
   Collins, Montana - Wooden Trestle Over Teton River 1900's
[You can see 150' Howe truss on the left side of this image.]

eBook2, p256

Sean Hanson posted two photos with the comment: "Got in some great rail fanning in Montana. My first time visiting the Great Fall Sub.  A local recommended this amazing view." The comments identified the trestle as being south of Collins, MT.

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A Bridge Hunter photo shows that the steel girders at the top of the towers are as deep as those between the towers. Since, as is typical, the distance between the towers is greater than the distance across the towers, the girders at the top of the towers are normally skinnier.

Great Northern got a lot of practice building trestles. Here is another one over the Kettle River near Sandstone, MN.