I've been researching our favorite pastime and have come up with the following. There is no Federal or Missouri State Law which prohibits Public Nudity.
The Federal Government leaves it up to the States, Missouri leaves it up to the Cities and Counties to do so if they choose. Heartland Cove happens to fall in Clinton County (the Clay County Line is approximately 1000 feet to the south)
I have not been able to discover if Clinton County has any public nudity ordinances. I suspect that since Clinton County is not "Online" it would require a direct inquiry at the courthouse. If anyone does make that inquiry let us know
For the Record Missouri Statutes do define public nudity "Full or partial nudity", the showing of all or any part of the human genitals or pubic area or buttock, or any part of the nipple of the breast of any female person, with less than a fully opaque covering.
Translation = Thongs and translucent (wet or dry)bathing suits do qualify as "Public Nudity"
http://www.moga.state.mo.us/statutes/C500-599/5730507.HTM
Missouri Revised StatutesChapter 573 Pornography and Related Offenses Section 573.507 August 28, 2002
4. Notwithstanding any provision of law to the contrary, any city not within a county and any county may prohibit within such city or county any live public nudity within ten feet of any person observing such nudity.
(I suppose one could make the Argument that the State is saying it is perfectly OK for anyone to be nude as long as they are not within 10 feet of someone who might happen to see you)