Thanks for all the positive waves re: my new bridge, fellow LAFers!
I also appreciate the comments on my river terrain boards. I made them way back in 2015 and they've served me well.
Soon after finishing them I made the boxes & cut the blue foam for 3 more 2' x 2' river boards -- 2 straights & 1 x 90 degree curve…

…but they've been sitting on a shelf in my garage since then.
As you can imagine "finishing" them is a rather time and labor intensive process!
But now, years later, the real challenge will be matching the color of the water. Unfortunately I mixed a couple of different artist inks to make the shade of green. I think I still have the bottles (tho they may have dried out) but as you probably can also imagine, matching mixed colors is much more of a pain than just opening a bottle and using it. Looking back in it, I really wish I had kept searching for an "out of the bottle" shade that I could hav e been satisfied with to color the water, but at the time it seemed impossible.
My wife and I recently reached the next level of "Empty Nester"-ship, with the third of our 3 kids graduating from college and going to work full-time, and I've been gaming much more often than I had for many years. So now…
I'm gonna' try to do all the pre-resin pour work (which is a lot of work!) to prep the 3 new river boards in the coming months. Then I'll do some mixing and testing with the inks in hopes of getting a very VERY close match to the color of the water in the river shown above.
Gaining another 6' of river, including a second 90 degree turn, would be fantastic for my gaming -- hahah, & also for my gaming buddies and convention game attendees.
Of course you never know what new time-suck(s) life may hold in store -- good, bad or indifferent -- but I'm happy you guys led me to post this reply, which in turn led me to make this "River Expansion" plan, so thanks again!