Micro Engineering makes through- and deck-type girder bridges in 30' and 50' lengths, and Central Valley has a 72'-er. Campbell has 70'-ers in both deck and through types, and Walthers has through-girder overpasses.
For truss bridges, Walthers offers both a single and doubletrack version, and Central Valley has a 150' single track type.
The deck girder in the foreground in from Micro Engineering, while the truss is a Central Valley kit - it's based on a 1902 prototype.
The deck girder at this end is a modified Atlas through girder: I simply chopped off the rounded ends and replaced the deck with some Micro Engineering bridge track. The two girders are connected with styrene strips and sheet, not visible when viewing the layout.
This is another modified Atlas through girder:
And some Atlas deck truss types:
Lots of unfinished scenery, and some Micro Engineering 30' and 50' girders on the high bridge, while the lower bridges are all from Atlas.
Wayne