We stayed in a Cabin at the Bear Lake KOA and were quite happy with our stay.
We found the Cabin and the Bathrooms to be Super clean and the staff to be friendly and helpful. We actually killed our car battery the morning we were leaving and the staff was very helpful in getting us going again.
My only complaints would be that the pool could have used a cleaning (however, it was very early in the season and there had been a lot of rain and wind recently so this could be easily overlooked) and the fact that we had to Pay to use the Jump Pillow. I have not encountered that at other KOAs.
Oh and the "free Wi Fi" did not work.
It also felt a bit less secure than other KOAs - we were able to drive through without any notice before checking in, but the area is very quiet and seemed very safe so that was probably fine.

Overall we found it to be a pleasant little spot to spend a few days relaxing in the middle of our trip.

From the moment we arrived, things started going wrong. Our reservation was messed up and we didn't get the cabin we had reserved. So, after letting them know there was no hot tub in our backyard (we were not aware of this until we had moved all of our stuff into the cabin), we moved all of our things to the cabin next door. After making the bed and unpacking, we realized that the electricity (meaning no fridge or microwave or lights or heater) worked on one side of the cabin. So, we called the manager and he came to work on it. After another hour-and-a-half, he determined that things were not going to get fixed until Monday (it was Sat.) so we should probably move back into the first cabin we were in and just walk over to the backyard of this "faulty" cabin to use the hot tub. While he was working on things, we found several large sized bugs in the cabin, and I walked outside to see the hot tub and lifted the cover and got such a horrible, burning sensation in my lungs and nose when I lifted it, that I couldn't breathe properly for 20 minutes. So, we moved back to the first cabin, and found that for the remainder of the trip we had no hot water, no wireless internet as promised and two pesky, annoying dogs in the yard right behind us that bark incessantly throughout the morning from about 6-11 am. The only redeeming part was that the manager credited a large portion of our bill back to us, but I wouldn't have stayed there for free if I would've known the hassles ahead of us. Boo on KOA. Never again.

The KOA at Bear Lake was great. There was a swimming pool, miniture golf, pancake breakfast, and hay rack ride. The children enjoyed it tremendously. It's just across the road from the lake itself so there is easy beach access. The trees there aren't much for shade b/c they have not fully matured yet. Would highly recommend it for camping.