The closest airport is Denver International Airport (DIA). There are a number of car rental options available at DIA. It's a 60 mile drive from DIA to Idaho Springs where the ceremony and reception will be. The drive can take anywhere from 1-1.5 hours depending on traffic.
The closest hotel chain is the Comfort Suites Golden West on Evergreen Parkway. This is about 12 miles from our home where the ceremony will be (15 min drive), and about 16 miles from Blackstone Rivers Ranch where the reception will be (20 min drive).
Blackstone Rivers Ranch will be opening some renovated riverfront cabins, Water & Stone Retreat. It's located less than a minute down the road from Blackstone Rivers Ranch.
If you prefer to stay directly in Idaho Springs, I recommend renting out a house/cabin/condo through Airbnb or VRBO as the motels in town are not the nicest.. I've listed a few that are nearby:
www.airbnb.com/rooms/14614632
www.airbnb.com/rooms/3821821
https://www.vrbo.com/7497363ha?arrival=2020-06-17&departure=2020-06-19
https://www.vrbo.com/7760724ha?arrival=2020-06-17&departure=2020-06-19
https://www.vrbo.com/554687?arrival=2020-06-17&departure=2020-06-19
www.airbnb.com/rooms/20805184
www.airbnb.com/rooms/14283785
www.airbnb.com/rooms/21730662
If you can't find any Airbnbs/VRBOs around Idaho Springs, there are a number of older motels at affordable rates. Be warned that these are very old and run-down! Only consider the below motels if you're willing to rough it up.
https://www.bearadisemotel.com
https://www.argoinnandsuites.com
Summertime in the Colorado Rockies can be a very popular time of year so rooms may sell out fast! I would recommend giving yourself ample time to find accommodations.