I-70 St. Louis to Denver
In Hays, Kansas:
1. AL'S CHICKENETTE: 700 Vine St, Hays, KS, 785-625-7414
Established 1949, this is one of the longest-running restaurants in NW Kansas. The draw is the eccentric fried chicken, which is crisp and dry. One of us had the chicken-fried steak instead and enjoyed that. Good fries, lots of skin. The salad was the least fresh I've ever finished, but I was glad to have it.
2. GELLA'S DINER AND LB. Brewing Company 117 E 11th St Hays KS
(these suggestions are from other people's Chowhound posts)
you'll find much more interesting things along rte. 50 from STL. from Lawrence to Topeka take 6th street which morphs into rte. 40 and back into 6th in Topeka then switch over to 24, hooking back up with 70 (never far away if you despair) near the Colorado border.
you will get screwed on time...
Depending on when you leave St. Louis, I'd recommend Ernie's Cafe in downtown Columbia, Mo. Great breakfast spot (and breakfast is served until 3 p.m.)
Or, skip the stop in CoMo and save room for some Kansas City BBQ. Plenty of threads on KC 'que around here, but I will put my 2 cents behind Arthur Bryant's.