My daughter and I will be driving to Denver in October. We plan to take four days. Does anyone have any recommendations for the journey -- which route? things to see along the way (though we don't have much time)? where to spend the nights?

Thanks for your good ideas.

That's 2000 miles, 500 per day, 10 hours behind the wheel if you stop to use the toilet once in the morning, once at noon, once in midafternoon.

Doesn't leave much time to see anything.

If I had it to do, it looks as if there would be less traffic and marginally more scenery on I-70.

It might not take you more than 3 driving days. 500 miles the first day will get you to the Mississippi, and I have often driven from an hour from St. Louis (as an example) for the second long day, but it is just driving.
I drive I70.
I am offering this because you might find some things east of the Mississippi to stop for and can still make your destination.
Don't be fooled that when you reach the Colorado border you are "there"!! It is another 4-6 hours to Denver!!

My choice would be I-70 but only because I can't tolerate the I-80 stretch around Chicago. I don't know what your driving style is but I have easily made the trip from DC to Denver in 3 days a couple of times.

If you go on i 70, you could stop and do the St. Louis arch, or stop at Cahokia Indian Mounds, just east of there in Illinois. I've driven both i70 and i 80 and there were more trucks and the adventure of going through Chicago with many other people on 80. For those not used to it flat land gets old, but you might see some antelope with the cattle as you get west, and you get great views of weather brewing. Get some books on tape, or take turns driving and reading, stop and walk around more often than you think you need to.

Oh, yes, books on tape a necessity. You can do unabridged!!
Chicago is a mess no matter how you cut it.

PA Turnpike, and then get toward Columbus OH, and it I70.
The Arch is a really neat monument. It will surprise you when it appears.