The Outdoor Discovery Series sponsored by the Butler County Parks and Recreation Department will feature "Turtle Talk" with Greg Levish at 7 p.m. tonight at the Carousel Shelter at Alameda Park, off New Castle Road. Admission is free. Call 724-284-5383.

Moraine State Park will be the site of "Explore the Source" at 10 a.m. Saturday for a moderately strenuous kayaking experience. "How to Plant a Native Garden" will begin at 2 p.m. Saturday at the former Marina Restaurant located just before the Davis Hollow Marina on the North Shore. "Learn to Kayak" will begin at 1 p.m. Sunday from the McDanel's launch on the North Shore. Call the 724-368-8811.

McConnells Mill State Park, Slippery Rock Township, just over the Butler County line into Lawrence County, will be the site of "Whole Grain Goodness" at 2 p.m. Sunday, meeting in the mill courtyard to participate in a corn grinding demonstration and see grains in action. the Mill is open through Labor Day featuring the restored rolling gristmill from 11 a.m. to 3:30 p.m. Fridays and 11 a.m. to 5 p.m. Saturdays and Sundays. Interpretive tours of the historic mill, which include a corn grinding demonstration and last about 45 minutes, will be available at 1 and 2 p.m. Fridays and 1 and 3 p.m. Saturdays and Sundays. Group tours may be scheduled by calling 724-368-3612. Other times are available by appointment. Call 724-368-8091.Pittsburgh

Rodef Shalom Biblical Botanical Garden, 4905 Fifth Ave., is open 10 a.m. to 2 p.m. Sundays through Thursdays and noon to 1 p.m. Saturdays through Sept. 15 as well as 7 to 9 p.m. Wednesdays through August. The current exhibit is "Lookin' Good Then and Now." Admission is free. Call 412-621-6566.

<B>Powdermill Nature Reserve</B> at 1847 Route 381 in Rector, the biological research station of Carnegie Museum of Natural History, is the site of the traveling exhibition "Art for Nature's Sake," which commemorates the 75th anniversary of the Federal Duck Stamp Program. The exhibition, organized by the Cincinnati Museum Center, contains 36 signed waterfowl prints and accompanying U.S. postal stamps, created by noted nature artists like Maynard Reece, the Hautman brothers, John Ruthven, Nancy Howe, and Adam Grimm. Call 724-593-6105.