No charge park but make sure kids have life jackets as there is a strong current.
Keep walking down the pathway past the divers area. Passing them will lead you to a cement trail, continue ~30 yards SE. You'll see off to RT a dirt pathway which leads you to a calm pool where the rapids have ceased. However there aren't any areas safe age regardless, children must always have an observer as they're only lifeguards during certain hours near the rapid area's.
As far as I know, it is free to access the river. Minor children under 10yo should probably avoid the main swimming area. There are many divers. More over, the water is quite deep through there, and year round. Quite safe for any strong experienced swimmer, age regardless, but do be educated and careful. Life vests are something one should consider. There are lifegaurds on-hand during certain times of the day. The safest, most "wholesome" spot is just up river from the main swimming area. It's a short walk along the water-front (rocky) south and east, and generally near/under the pedestrian bridge. Late in the season the water is at its lowest level and knee deep at the shore. A stroller is out of the question throughout the whole area. Also, handicap access is minimal.
The park is free. Yes there are a lot of kids there.
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