The closest major airport is Denver International Airport, also known as DEN or KDEN, located at a distance of 34 miles from the city center of Boulder, CO, in Denver, CO.
The driving distance between Boulder and Denver can be easily made in 35 minutes, the cost of the fuel being about $6 for a round trip.
Denver International Airport is open 24h/day, offering non-stop daily flights to more than 130 major destinations. Travelers can request information regarding transportation at the Ground Transportation Information Counter, situated at Jeppesen Terminal, on level 5, open daily between 6 30 am and 11 30 pm.
A car is not necessarily a must-have in Boulder, because the city has an excellent bus system. There are multiple parking areas, anyway, especially downtown, that are often free on weekends or after hours.
Boulder City has an excellent bus transportation system, provided by the Community Transit Network (CTN), offering numerous buses that run inside the city, also providing routes outside the city. The regular bus fares start from $2 (Cash) and can cost up to $70 (Monthly Pass).
Boulder is a bike-friendly city, providing a huge network of bike paths, making easy for those who wish to get to their intended destination fast, inside the city, avoiding the traffic and stop lights, especially during rush hour.
How to get to UCB from Denver
From Denver, drive west on U.S. 36 and exit at Baseline Road, make a left here, and than turn right on Broadway, and you're there!