We are planning a trip to the Denver area in August for 5 days.
Looking for ideas on things to see and places to stay.
We want to include Rocky Mtn National Park.

A frequently asked question. Put Colorado in the search box and you will have a couple hours of reading.

You'll want to avoid Denver during the Democratic convention August 25 - 28th

Spend more time in RMNP / Estes, less time in Denver.

The mountains are gorgeous in summer. Denver will be hot and humid - the mountains will be cool and dry.

Denver - humid???
Agree with Dick & add a couple of days on either side. Mountain venues may be busy before & after the convention,also.

Don't think gofrank50 lives in Denver.

I don't think he does either. However he may have been here during one of the Cherry Creek Festivals which is the only time I remember it being hot and only slightly humid.

Reality is that it is more humid in the mountains than on the plains. It is just cooler in the mountains.

So, back to the question and Fmpden is correct--lots of threads.
But if you want to do a nice day trip, drive up to the RMNP, drive through on TRail Ridge Road and come down the other side to Silverthorne, and then back to Denver.
There is a really nice butterfly pavillion in Westminster--and it WILL be humid there!!--that is sort of on the way to Boulder for another pleasant day trip.
Lots of things to do in Denver proper for any number of days. Nice botanical garden, zoo, museums, eating downtown, Rockies games, shopping.

If you haven't been to Colorado, you should stay in the mountains a couple of nights. Grand Lake would be on the other side of Trail Ridge Rd. Cabins, etc. We like Breckenridge & Glenwood but I wouldn't do RMNP and Glenwood. One or the other.