Finally got it finished. Found some 8ft galvanized pipe used for scaffolding and spliced 2x8x16' pressure treated boards along the length. Made a few mistakes along the way, which is normal. Made things harder than they needed to be but it's structurally stable. Thanks for all of the input. Not sure why my original pics are not viewable anymore. Hope these are.

The old bridge and new bridge.

Attached Images
IMG_20220928_185015_945.jpg IMG_20221007_123903_561.jpg