there is a koa in salina and another 2+ hours west.
there is a nice private cg ~10 miles south (closer to little sveden) near lindsborg...
there are state parks and coe parks at the lakes north and west of salina (glen elder and wilson)
there are many private rv parks and IF you have access to a TL or woodalls book, many are listed.
some of them are listed on these 2 websites...
Kansas RV Parks & Travel, Inc. - RV Parks & Campground Directory
Free yourself - Camp Kansas!
we briefly played with the i70 info here...
heading north on 81 (from salina) there are several campground along the route (concordia, belleville)