Ok here are your options.
*SDC/CC - 6miles apart - 10-15minutes (depending on traffic)
*WOF/SFStL - 253miles apart - 4.5-5hours
Let's just think here, why not go to SDC/CC this trip. Both can easily be done in the same day without doing a rush job, save the other two for another trip later on this year and PLAN A SEPERATE DAY FOR EACH. There is no way that you can go to both parks (a actually get your moneys worth and actually SEE the park) and then travel that long of a distance.
------------------
SW:):)SH
midwestinfoguide.com