Biking and fishing?

Hey gang,
I’m looking for some good fly fishing spots to access by bike. Was thinking there’s probably some good spots along the BLT or St Margaret’s bay trail. I would be taking my 74 yo dad who’s pretty active and spry for his age, he can do the crushed gravel easily, then maybe up to a 10 min hike in?
I’m not looking for anyone to divulge the exact coordinates of their magic trout hole, but some basic access points would be great.

Square Lake in Beaver Bank, and the surrounding lakes and brooks. Perfect spot. We love it there. Google it!

Looks like a cool place, any tips on how to access it? Thanks!