Harrison Spring, near the Blue River north of White Cloud, is Indiana’s largest spring and one of its most important karst features. Water from Indian Creek and other sinkhole plains travels through a vast subterranean drainage basin to emerge here, and studies suggest possible links to Binkley’s Cave, the state’s longest known cave. The spring’s rise pool is large and deep, and its flow is powerful enough to average 100 cubic feet per second, with much higher flood discharge. Named for William Henry Harrison, whose nearby farm once used its water to power early mills, the spring was recognized as a National Natural Landmark in 1980.