Right now the only places I'm planning on stopping along the way is St Louis (a couple hours) and Rocky Mountain National Park (one night).

Are there any really cool quick places to stop along the way besides these two places? (no more than 30 minutes off the highway, and don't want to spend more than an hour there)

Thanks!

Where are you joining up with I70? I would think you'd take I40.

https://www.google.com/maps/dir/Gree...d37.865101!5i1

Idk if that link will work but I'm going this way, its the same time as 40, but this way takes me close to Rocky Mountain National Park

That's a lot of Kansas.

Do you really want to go to St. Louis or is it on your visit list because it is on your route?

If I were making this trip and wanted to see the Rockies, I would take I-40 all the way to Albuquerque, then north to Santa Fe, Taos, Salida, Colorado, then join I-70 near Breckinridge.

If you absolutely, positively have to go to RMNC, you can turn east for a bit to Idaho Springs, and take the beautiful 2 lane through Nederland to Estes Park, drive through RMNC to Granby on US 34, then rejoin I-70 via US 40 or CO 9.

You can't do this in the winter, of course.

If going up 15 to 70, Zion Natl Park is a good pick

Having driven to Denver from Charlotte numerous times, the arch is indeed right on the highway.

Missouri, Kansas and eastern Colorado are just putting in time--you can do the math for the time--but there isn't much in the way of a stop. Charlotte to Denver is 1600 miles--I do it in two days, with a stop in either KC or Columbia MO, arriving Denver mid-afternoon, so theoretically I could get to Estes Park that night instead. Just for an idea.
You don't say if there is more than one driver so you are driving straight through.
RMNP is "close" to Denver but still more than an hour. You can drive through the Park, and "down" the other side to get back on I70 to head on west. Ack has given you that "drill".

I think the drive through the mountains on 170 is beautiful. Not sure that Ack's idea of the southern 40 route through OK is "better" than Kansas!!

"no stop longer than 30 minutes"==my observation of this--why bother.

Pull in for a soak in the huge outdoor hot tub at Glenwood Springs, Colorado. You can see it from I-70.