The public is invited to bring Indian artifacts to the Nygren Wetland Preserve for identification by archaeologists during an open house on Saturday, Sept. 27. The event is hosted by the Natural Land Institute and is free and open to the public from 10 a.m. to 2 p.m. In addition to identifying artifacts, archaeologists will tell about the latest surveys of historic and prehistoric sites at the preserve. They will describe how the presence of debris from flintknapping and fire-cracked rock indicate that all stages of tool manufacture took place on about four acres and provides evidence of a campsite of some duration during at least one of the prehistoric occupations. A presentation on the archaeological history of the site is scheduled for 10:30 a.m. Guided tours and wagon rides to Raccoon Creek are available at 11 a.m. and 1 p.m. The Natural Land Institute is returning the creek to its original, meandering channel to function as a living stream for wildlife. A presentation on changes in plant cover is set for 11 a.m., a guided bird watching tour for 10 a.m. and a program on bird populations at 12:30 p.m. The event also features a program on turtles and tours of the native plant nursery and the Native American longhouse. The Nygren Wetland Preserve is located one mile west of Rockton at 3190 West Rockton Rd. Information: 815/248-4697.