With a 24' trailer, you could stay at any of the campgrounds within the park and I would recommend that you do. The GNP website has a page on the status of the campgrounds and fill times. If you need hookups, then there are many RV parks outside the gate. Mountain Meadows and the KOA we've stayed at on the West Side and the KOA on the East side is good too. Visit all the sites within the park taking the time to stop at Lake McDonald and walk the shore to see the colorful pebbles at the shore. On the South side around the park on Hwy 2, stop at Goat Lick. The Goats travel there every day to lick the salt there. We've been there three times and still see something new.