Fun tank idea! I'd definitely recommend a larger tank if you want to plan on keeping any of those species for awhile, though. If you can manage a 40g tank, you could grow probably grow them up to about 4-5" without too much worry. Even a 29g tank would give them a bit more space to live healthily until you release them back to the creek!
My brother used to keep bluegills and bullhead [to full size!] on occasion in a 75g tank with a rock bottom like you have. It's really fun as a sportsman to see game fish like this mature, just keep in mind they're going to need large tanks to make it to maturity in good health. Smaller specimens and juveniles will do alright in 'little' tanks, but do be mindful to release them safely before they outgrow their surroundings
And not to be Johnny Buzzkill, but make sure you're able to legally hold them in your state/province. It may not be legal to hold/transport wild gamefish without a license in some areas and the DNR doesn't eff around with that kind of thing. As a kid, a less-than-pleasant agent once gave my friends and I a dressing down for catching turtles and crayfish in the creek by my old house; made us release everything on the spot