Sacramento River Suspension Bridge
Photo from River Dancers
License: Creative Commons Attribution-Share-Alike (CC BY-SA)
View this photo at riverdancers.com
BH Photo #465996
https://livingnewdeal.org/projects/upper-sacramento-river-si... and I just found that, with photos and a statement that it was to provide fire access.
https://binged.it/2SxwzpP Bing has a street view of it, both portal and (limited) from the side. I suspect that it was originally a road bridge, as it's significantly wider than most pedestrian bridges. The SE end of the concrete bridge is marked 1974 so I suspect that's when it was replaced.