Great sites and hosts, cannot swim in lake
Stayed 4 nights at Indian-Celina on the South loop with some friends (sites 25, 26, and 27) during August 2020. Overall, we had a great time. The sites are pretty spread out and private, the bathrooms are clean, and water spigots are everywhere. The hosts are friendly (there are two, one for the north loop and one for the south loop), and are who you buy wood/parking signs from.
Unfortunately, despite the udsa.gov website mentioning this was a swimmable lake, both the Indian and Celina lakes do not have a beach and cannot be swam in. Thankfully, there's a beach on Tipsaw lake that's about a 10 minute drive away that allows for free day-use if you have an Indian-Celina tag.
Electric hookups are solid and we were able to pull 24 amps consistently from the TT-30 outlets. Cell service on Verizon is very spotty and the general assumption is that it doesn't work. But still good enough to send out an occasional text.