Ohiopyle State Park, one of Pennsylvania's Top Five State Parks, imo. And not just because if offers some fine intermediate level whitewater boating. It also has great hiking trails. A famous regional rail trail passes through the park. It has excellent camping facilities. It is centered in a fun little town that is dedicated to outdoor recreation. It is near many other wonderful hiking, biking, and boating opportunities nearby. It is open for winter sports. Need I go on?
This roughly 20,000 acre park (more than 30 square miles) is built in the hills and valleys formed by the Youghiogheny River. The gorge carved by the river may be the centerpiece, but there's lots more. I've paddled the river maybe a hundred times, times, biked the rail trail maybe a dozen times, hiked maybe eight of the trails, and camped there maybe a half dozen times.
Its scenic beauty and multiple recreational opportunities make this a rock star park, which is kind of a blessing and a curse. It takes a lot of people to make outdoor recreation profitable and great. On the other hand, there's potential for lots of people on the river, one the hiking trails, and on the bike path (it is part of the Great Allegheny Passage rail trail). If you like crowds, go for it. Most everyone is happy and friendly. If you prefer more solitude, wait for shoulder season weekdays; you are more likely to have a little part of paradise to yourself. One of Pennsylvania's best!