Most people use a lead head jig and plastic lure (twister tail or similar) and a small piece of sucker meat for flavor (available in the freezer at Sportsman's etc). But, you have to get your presentation to the fish. This time of year you are not going to find them near the bank; they like the deeper water. Get out there with a float tube or boat and you might have a chance. You can find them closer in to the bank in late fall or early spring.
Drive the road on the south side of Granby back towards Arapahoe Bay. There you will find cliffs that go straight down into deep water. A kastmaster or other heavy spoon jigged deep in the rocks may work. Tough fishing from cliffs and lots of snags. However this is your best chance to catch a decent laker from shore right now.
You have to have realistic expectations. The lake trout you are after are deep now and will be for the rest of the summer.
Lake trout are meat eaters and usually will not hit a fly. Although, they'll hit a hair jig. And you can get them to bite in reaction to a properly placed active lure like a rapala. So yeah, you could get lucky and maybe get a hit on a rooster tail or streamer, I guess, if you could get a good long cast maybe with a weight or something. But then you are going to get hung up on the bottom. You could get lucky, I'm not saying it could never happen. But your time could be better spent.
Consider a trip with Bernie at Granby. You and your kids will have a blast and you'll learn all you want about catching Lake trout. ;D
Thanks albow. That’s an appreciated informative answer. I may take a stroll down the river with the fly rod. The kids aren’t quite up for that though. We will be camping near the waters edge. I thought we could catch some there last time. But, not even a bite. I did hear fish jumping in the middle of the night. So, they’re there!
have you tried a slip bobber with a white tube jig and sucker meat you can cast out as far as possible and let the wind do the jigging for you another spot would be gross reservoir you can access deep water pretty close to shore and not as far of a drive
you need to be pretty close to the bottom so you'll have to guess at depth but you should be able to tell by how your bobber is reacting if its laying sideways your on bottom if its moving along at a fast clip you probably need to set it deeper experiment and I bet you'll get into some