When does the swimming area close for the season?

From what i am told an wad told twice it doesn't because of it being a river .

The whole river is open to swimming. The actual swimming area that was created way back in the day is also open and free at all times. The park tried to make money creating the swimming area, but did not work out as people didn't find it necessary to pay money to swim in that particular area when the rest of the river was free. However, the swimming area is less rocky, open, and still has a sandy bottom. Also, the river is mountain water and can be very cold to swim in. Late June to early August is about the only time swimming is feasible there.

It doesnt

You swim In the river so I doubt it closes