Caddo Lake State Park will celebrate the Texas Park system’s 100th anniversary and partner, Caddo Lake Institute will celebrate 30 years of science. April 14, 8 p.m., an outdoor showing of Harry and the Hendersons. April 15, outreach tables, local presentations, and interpretive hikes from 11 a.m. to 5 p.m. The sock hop will be from 7:00 to 9:00 p.m. in the CCC recreational hall.