"Railroads of Caribou" at the Caribou Historical Center and Museum. Open 12-4 p.m. Saturdays; 1033 Presque Isle Road. All are welcome.

Farmers' market at Riverside Park, 8:30 a.m.-1 p.m. Vegetables, meat, eggs, baked goods and more. Concession available.

Aid for Kids Educational Fair, 10 a.m.-2 p.m. at John Millar Civic Center. Free; includes barbecue, puppets, law enforcement demos, science/animal exhibits, crafts, games and prizes.