Beach report of sorts (and a question or two...)

So, a few weeks ago, got some info on an out-of-the-way beach to try for SRC's. Got lost, ended up trying a different spot first, all I got was a sculpin (which, to be fair, was the first SW sculpin I've ever gotten!) Ended up finding the initial desired spot, over two trips managed my first SRC, small one, but still!

Anyway, fished yesterday at a new spot, one that I imagine gets some pressure, but no one was around all morning. Fished for 2 hours without a bump or seeing a thing, then, at absolute dead low tide, saw some res coho jumping everywhere a ways down the beach. Hustled my fat butt down there, and ended up having a blast, got quite a few, including 2 that were noticeably larger than all the others, almost like they were a different age class or something?

Questions- when the coho are jumping like that, what are they doing? I'm sure you know what I mean, full airborne, dolphin style. They're not chasing bait to the surface that I can tell, are they teeing to delice or loosen egg sacks? (the way female carp will jump pre-spawn to break their egg clusters.)

Do you generally find SRC and coho do not intermingle, or do you get them at similar times and locales?

Are there separate age classes that would explain why 2 if the fish were bigger? I'm talking about most being 11-14" while these 2 were about 20" or so and pushing 3 lbs I'm guessing, fat and solid.

Thanks all, hope to keep seeing some new water. I've been living here for 8 weeks now, and it has been a blast exploring and stomping around the woods and rivers and beaches.

Oh, one last question (thanks in advance btw...) If a bridge crosses an estuary, and there is ample room to park and there aren't any "No Tresspassing" signs, what is the access legality to both get to the water and then once in the water (below tidal line?)