Southwest PA, particularly the Laurel Highlands is a wonderful area in which to spend a quality time. The area is easily accessed on your trip from St. Louis by following Interstate 70 E through Ohio, West Virginia, and into Pennsylvania. Pick up the PA Tpk in New Stanton for 15 miles, and take the next exit (91) at Donegal. Turn left on US Rte 31, and you'll be in the heart of the beautiful Laurel Higlands Many State Parks and activities are available by searching the DCNR Homepage
https://www.dcnr.pa.gov/Pages/default.asp
I would highly recommend the Flight 93 Memorial (9/11 crash site), Frank Lloyd Wright's Falling Water and Kentuck Knob home tours by reservation and ticket. Seven Springs and Hidden Valley Mountain resorts are summer activity meccas, as well. The historic town of Ligonier, located on US Rte 30, with ties to George Washington and General Braddock in the French and Indian War era, is worth a visit. Also located on US 30, you can find Idlewild Park and Story Book Forrest. This nostalgic theme park has entertained countless generations of visitors. It's a tradition to pack a picnic basket/cooler for your lunch in the park's pavilion.
We have enjoyed camping at Laurel Hill SP (a little off the main road), and Kooser SP, with easy in-and-out access to US Rte 31. Kooser can be a bit noisy with highway truck traffic, but the location makes it very convenient for travel to any of these points of interest. Due to the July 4th holiday, availability will be limited. Reservations will likely be necessary. There are other privately-owned, quality campgrounds in the region. Search the Somerset, Fayette, and Westmoreland county areas for more information.
Ohiopyle SP, and the town itself offer exciting whitewater rafting, biking, and hiking opportunities. However, be forewarned, traveling to its Kentuck Campground requires careful route planning for large RVs and campers. Read carefully the fine print on their reservation page for recommendations for arrival.
Wil, Tara, Keeko (Jack Russel/Chihuahua mix 9 yr.-old) and Kalee (Wire Hair Terrier/Blue Heeler mix 1 yr. old)
2018 Rockwood Ultra-Lite 2702; 2014 Dodge Ram 1500 Big Horn Crew Cab 5.7L Hemi w/ 3.92 rear axle