Missing the campsite might seem like a fail, but those wrong turns make the best stories later. Letting kids take the map teaches them to figure out problems in a real way. My nephew once guided us to a dead end, but he learned to read signs after that. The creek trip probably gave your family a funny memory to share for years. Plus, kids gain so much confidence from trying, even when they mess up.
Oh perfect, a creek is basically a campsite with more mosquitoes and wet socks, right? My kid's map reading once got us to a "scenic overlook" that was just a dumpster behind a ranger station. At least you found water!