Explore the Wissahickon Creek at the Four Mills Reserve. Investigate how fast it flows and hunt for eddies, riffles and other stream features. Explore using nets, buckets and tools to find out what critters are living in our back yard. Dress for the outdoors Registration required; Members and children under 12: free | Non-members: $10.00 To register, call the office at 215-646-8866 or Register online.