Took everyone out on the boat and forced the Alabama cousins to swim in the "freezing cold" Missouri River. My family lives right on the Tennessee River in Alabama (I come by my river love naturally), which is much much warmer than the Missouri. They got over the cold. Tubing was a huge hit.
Took a walk in the woods to look for bald eagles. We didn't find any, but the kids loved these giant trees. The white lines are the flood lines from 2011. Anna (6) is the only one willing to catch a frog.
Went to play on this walking park in our town. It's like a playground but each structure is several hundred yards down the path from the next, so they get a lot of walking/running in.
Took them on a Black Hills tour- we saw Mount Rushmore, Custer State Park (sadly, no buffalo), the splash pads in Rapid City, and I took the girls went through the Badlands on the way home.
Mike and I took a 48 hour mini-vacation to Sioux Falls with no kids. We shopped, ate, ran, and drank beer. It was terrific.
Next year we are probably headed back South, but it was really awesome to get to have Ryan's kids here and I'm betting it's memories they will never forget. "The summer we went to South Dakota!"