World of water

Fort Snelling State Park

1-2 p.m. Saturday

Minnesota rivers rise and fall, usually on a seasonal cycle, but every now and then they rise too high — to sometimes bad results. Where does all this water come from and why are some floods so disastrous? How have humans reacted to flooding, and is there really any method to control floods? (612-725-2724, mndnr.gov)

Beaver basics

Wild River State Park

2-3:30 p.m. Saturday

Join the naturalist for a brief introduction before heading out on the trails to visit a couple of beaver dams and view some nearby lodges. (651-583-2125, ext. 227, mndnr.gov)

Bison tours

Minneopa State Park

10:30 a.m., 11:40 a.m. and 12:50 p.m. Saturday and Sunday

Ride through the bison range with a naturalist and hear more about North America's largest mammal. Learn about the park's bison herd and some of its unique characteristics. Registration required. Visit mndnr.gov/reservations or call 866-857-2757. Tours are $8 for adults, $5 for ages 5 to 12, and free for children younger than 5. Tours start at the group campground on the campground side of the park. (507-384-8890, mndnr.gov)

Orienteering skills

French Regional Park

Noon-3 p.m. Saturday

Learn to find your way in the woods the old-fashioned way, with a map and compass, with training from the Minnesota Orienteering Club. There will be stations geared for beginners, guided practice courses and an official "sprint" course. A special session is available for teachers and group leaders. Cost is $13 for those who preregister and $18 day of the program. Call 763-559-6700 to register and reference activity 225058-00. The program is for ages 6 and older. (threeriversparks.org)

Bird-watching trek

Minnesota Valley National Wildlife Refuge

8-10:30 a.m. Monday

Join a bird-watching trek at the Old Cedar Avenue trailhead of the Long Meadow Lake Unit in Bloomington and learn about the birds that visit the refuge during their spring migration. Birders of all skill levels are welcome. (952-240-7647, bit.ly/MNvalley)

Stalking woodcock

Eastman Nature Center

6:45-9 p.m. Tuesday

Learn the natural history of woodcocks. Rush for position at dusk as the male swoops and twitters in a high aerial dance. Cost is $5 and reservations are required. Call 763-559-6700 reference activity 212228-00.