I found in Carl Bajema's
The Lake Line: the GR, GH & M Ry two pictures of the aforementioned interurban bridges over Crockery Creek near Nunica.
Pardon the craptastic photos.
First, the main bridge over the creek for the Interurban. I guess the IU really didn't have an elevated ROW, you can see the GT off to the left, and much above. Their bridge is just out of view. I'd in interested to know the build dates on those bridges...JT you should have tried to find the builder's plate!
The second one shows the IU working to repair sinkholes following significant flooding. I'm guessing the image was taken from the GT grade, given the heading of looking NE.