Within the Schuylkill River Valley, Blue Marsh Lake is a man-made lake along Tulpehocken Creek with numerous boating, hiking, biking, and birdwatching opportunities. Created for flood control, the lake has turned into a popular recreational hotspot. This 1,147 acre lake brings numerous outdoor enthusiasts to enjoy the water, picnic areas, a small beach. There is a fee per car in the summer, but not throughout the remainder of the year.