10 Best Days of the Bakken: Themed days with exhibits and activities include Minnesota Makers, Garden Variety Day and Sunergy. Also the Green Energy Art Garden, a green rooftop where artists work with visitors to create science-inspired, eco-electronic art and music. 10 a.m.-5 p.m. Bakken Museum, 3537 Zenith Av. S., Minneapolis. Free.
Twin Cities River Rats: Waterski show. 3 & 7 p.m. Mississippi River -- downtown Minneapolis, between Broadway Avenue Bridge and Plymouth Avenue Bridge.
10 Best Days of the Bakken: Themed days with exhibits and activities. 10 a.m.-5 p.m. Bakken Museum, 3537 Zenith Av. S., Minneapolis. Free.
Twin Cities River Rats: 3 p.m. Mississippi River, between Broadway and Plymouth Avenue bridges, Minneapolis.
Aquatennial Beach Bash: Milk carton boat races and family activities. 10 a.m.-4 p.m. Thomas Beach, Lake Calhoun, William Berry Pkwy. and E. Calhoun Pkwy., Minneapolis.
Sister Cities Day Celebration: Entertainment, ice cream and activities to celebrate Minneapolis' 10 sister-city relationships. 1-5 p.m. Nicollet Island Pavilion, 40 Power St., Minneapolis. Free.