Probably one of the nicest big rig friendly parks in SE Connecticut is Aces High in East Lyme. Granted it is not the closest to Foxwoods or Mohegan Sun, but is probably the best for big rigs and has full hookups with pull thrus. I have used it several times when passing thru eastern CT. If you happen to be retired military, they give a discount. It is in East Lyme, CT. One word of caution, CT campgrounds do not all have sewer hookups. So, if you expect sewers, take a good look. If you are going to spend all your time in the casino, stay in their lot.
2008 Itasca Suncruiser 38T
2012 Ford Explorer