East Canyon Campground

Big Rock is pretty but you'll be sharing your space with huge herds of sheep and all their BAAAAing at night. We stayed for 4th of July because all the other campgrounds in the area were full.
A very large group stayed in the spot next to ours, put up 8 tents (yes the spaces are that big) and proceeded to talk, drink and screw all night. If you need a space that will allow that, this campground is it as it's not policed at all.
The river running through is pretty but the still water has worms and the plants all have thorns so it's hard to bushwhack your way through. There is no tree cover anywhere and it gets plenty hot. Cell connectivity was very low for the entire area so bring a map.

The Big Rock Campground is one of my least favorite campgrounds. Located on the south end of the lake, it's far away from the amenities found in the Dixie Campground, and offers very little in the way of shade or...well...anything beyond pavement. The campgrounds are close together, offer no privacy, and no trees. The trail down the lake is poorly maintained, and the shore is muddy, stinky, and gross.

The reservoir itself is nice except the south end) and is a great place for a day trip from Salt Lake or Layton. The Dixie Creek campground is developed, has sandy beaches, a boat ramp, rentals, and snack bar. (You're not exactly in the wilderness here).