I would recommend seeing the capital and people watching at Pearl St. Mall in Boulder,you’ll get a kick out of it.You have to check out the Denver natural history museum and possibly the Denver zoo as well.Mesa Verde National park,Florissant Fossil Beds,Pony Express National Historic Trail, Rocky Mountain National Park are very cool parks to check out.
Grand Mesa,Pike,White River,Roosevelt,Arapaho are some forest you should check out as well
I’m definitely going to check out Boulder with the Pearl St. Mall, Celestial Seasonings Factory Tour and the Boulder Dushambee Teahouse. Should be a great trip. Thanks!