Was reading up on big tadpoles. Last week I had hundreds, if not thousands, that I videoed while they were up in shallow, shady water near the cabin. They were brown, not black and about 3 inches long. With this basic description, can anyone tell me what kind they are?

I would say bullfrog. They are normally brown and large. It can take 2 years for them to turn into frogs.

+1 on the tad being a bull frog

PS welcome to the forum