William O'Brien State Park Things to Do
Greenberg Island sits in the middle of the St. Croix River but really isn't accessible for people but a sign reads:
"Across this channel lies Greenberg Island, a haven for wildlife. Look... you may see a playful otter frolicking near the shore, a snapping turtle laying her eggs, or an eagle soaring overhead. Listen... you may hear a pileated woodpecker hammering holes in a tree, the gunshopt snap of a beaver's tail on the water, or the hoot of a barred owl.
"At times the island may be entirely underwter. The animals are free to leave and the plants that live here are adapted to tolerate 'wet feeet.'"
Named after Alice O'Brien who donated the land to the state and there is a swimming beach at Lake Alice and a boat launch.
Yes, they have an amphitheater. I don't know what performances take place here but I thought it was cool that it exists.