Rivnuts from Homestead, PA on 9/15/2023 2:52:56 PM:
The GAP Trail itself passes through Ohiopyle State Park and the town of Ohiopyle. Ohiopyle State Park is quite large. The Kentuck Campground is also located within this state park and has showers, water and electricity if you choose. However, as you note, it is nearly 4 miles from the town of Ohiopyle via road with the majority uphill with grades up to 15%. The ride up to the Kentuck Campground is not for the faint of heart.
Earlier this year five primitive camp sites with picnic tables and composting toilets were developed for bicyclists directly on the trail itself at mile marker 72.6 near Ohiopyle obviating the need to ride up to Kentuck Campground albeit with no showers. You'll find the announcement of these sites at the gaptrail.org website.
Whichever you choose, you would need to make a reservation via the PA State Park Website.
Note there is also a campground virtually on the GAP Trail in Confluence PA some 10 miles south of Ohiopyle as well as one in Connellsville PA about 17 miles north of Ohiopyle. You may want to consider these as well.