I like this design - it is clear, easy to see and gets the message across. I like the readability of 'Smokefree Natrona County' in #3, but I do like the diamond background in #4 - it sort of feels enclosed, which is what we are trying to do, ban smoking indoors. Which is hard to signify in a logo. Can you please further develop and come up with some versions combining the larger text of #3 and the enclosed look of #4? Maybe just try making the 'Natrona County' in #4 larger?