Carpooling is recommended. It may be possible to take an Uber or taxi to the venue, but getting home could be challenging. The couple are looking into possibly having a small bus but is not guaranteed.
Two room blocks have been reserved:
#1 Holiday Inn Express & Suites Denver South - Castle Rock LINK - Booking code = PNW
&
#2 Best Western Plus - Castle Rock LINK - Booking code = Peters-Niessen Wedding (if clicking the link does not work, copy/paste this URL: https://www.bestwestern.com/en_US/book/hotel-rooms.06157.html?groupId=F57HX3F0
These two hotels are located adjacent to one-another and ~45minutes from the venue.
There are many other accommodation options with various travel times to the venue. You can also consider:
1. Airbnb
2. Hotels in Parker or Colorado Springs
3. Camping
Camping recommendation is to book EARLY at Casey's RV Hideaway
https://elizabethpr.com/caseys-rv-hideaway
You can fly into either the Colorado Springs Airport or Denver International Airport. Colorado Springs Airport is closer to the venue and could be more convenient for your travel plans.