We have traveled across 160 from Missouri to Colorado before but prefer traveling 400 although it does take longer than going north to I70. lots of small towns on both routes but never had trouble finding diesel
On 160 a nice state park is Elk City Lake ks state park. lots of first come first serve sites on the water but weekends are packed
on 400 we stay at Cheny Resevoir state park and go to the Kansas Comosphere in Hutchinson KS - awesome space museum and have also stayed in Dodge City and John Martin Reservoir St park which is on 50 before Pueblo Colorado