This would be an attempt to speculate "Where is this bridge NOW??"
When the Arkansas River Navigation program was going on, almost all bridges across the Arkansas River in the navigation channel had to be replaced, or rarely, raised to allow for the future barge traffic. We think we know that this bridge was composed of trusses from the pre-1913 Frisco railroad bridge spanning the Arkansas river at Van Buren. At least the trusses appear to be identical in style.
Of course the navigation project required this bridge to be replaced. The question is, what became of the trusses then? It was common for steel truss style bridge elements to be reused. Indeed the Morrilton Bridge trusses were "used" when the Morrilton bridge was installed. I think "maybe" I have found one of the smaller pratt style trusses that composed the Fort Smith entrance to this former railroad bridge. It is located on a county road in Oklahoma, about 30 miles from Fort Smith, Arkansas. Since this "may" have been an Arkansas bridge at one point I am attaching a photo. Also I am attaching an old postcard view of the Frisco bridge looking from the Fort Smith side, so you can compare the construction of the trusses. The lattice work from the portals is missing, replaced with simple portal braces.
This bridge is thought to be made up of spans from the "original" Frisco railroad bridge at Van Buren across the Arkansas river. The Frisco bridge was updated in 1913 with much heavier truss sections, and the old truss members were available for purchase. I have attached a post-card view of the bridge in its original location.