Travel
The best airport to fly into would be Denver International Airport (DIA).
If renting a car isn't in the cards for you, there is a shuttle system to Fort Collins through Landline and Groome. Fort Collins has 2 dropoff locations - the Harmony Transfer Center or the Colorado State Transit Center. This costs $30 one way per person.
Feel free to reach out if you have any questions, we'd love to help you!