Another Bridge Question - Steel Deck at milepost 416

Dave Dye has a “Randy Babcock photo of the steel deck at milepost 416. About 3 miles east of LaBoca” on his Rio Grande Narrow Gauge Site.

[davesriogrande.net]

I find this bridge interesting as it is listed as an 80 foot Deck Girder which would make it one of the longer, if not the longest, such bridge on the D&RGW narrow gauge.

Looks to be to perhaps be a standard gauge bridge that was moved to the Narrow Gauge to replace an older bridge.

Some questions

1) Where did the deck girder bridge come from?
2) When did it get installed on the Narrow Gauge?
3) What type of bridge did it replace?
4) What is the height of the girder?

Thanks

Stan