Rocky Mountain National Park is about a two-hour drive from the Mile High City, making it one of the best Denver day trips. The drive and the destination both offer spectacular views! Just about every spot at the park gives you a scenic view of the Rocky Mountains, and you may spot moose, elk, marmots, and adorable pikas roaming the park. Hikes in Rocky Mountain National Park lead to summits, waterfalls, and alpine lakes. The scenic Trail Ridge Road is a must for summertime visitors. It’s the highest continuously paved road in the U.S. and climbs to more than 12,000 feet above sea level. Rocky Mountain National Park is definitely one of the best places to visit in Colorado! But be sure to plan ahead — reservations are required during peak season.