Inside the Denver Airport. A round trip flight from Columbus, OH to Denver, CO with 2 adults and 2 kids cost about $290.00 with United Airlines.
Denver, Colorado is of course the capital of Colorado. Hotels can range anywhere from $80/night to $275/night. A good cheap option is the La Quinta Inn at the Denver Airport which cost $90/night. An excellent, but more expensive option is the Hyatt Hotel which cost $219/night.
Racca's Pizzeria Napoletana is third highest rated of all restaurants in Denver, Colorado that is known for their pizza napoletana and chicken wings. The prices for the pizza napoletana range from $14-$20 for an average sized pizza.
The Denver Biscuit Company is the sixth highest rated restaurant in Denver. This restaurant is obviously known for it's wide selection of biscuits and breakfast foods that you can get there for a great price.
Boulder Street Mall has lots of interesting stores that are lots of fun to walk around in. There are also plenty of street performers that serve as great entertainment. If you ever get hungry while walking around the mall, there are lots of small restaurants and bars throughout the mall.
The Flatirons are near Boulder and are lots of fun to hike up. There are several different trails you can take that can take you anywhere from the base of the Flatirons all the way to the top. There are great viewing points all throughout the hike that allow you to see all across Colorado. The hike is roughly four hours if you decide to go from bottom to top;however, there are lots of places to go which can make it last much longer.
Vail, Colorado is a city deep within the mountains that has a great downtown to walk around along with great mountains to hike, ski, mountain bike, etc. Vail is about an hour drive from Boulder, Colorado but it is a very scenic drive as it takes you through the mountains. Hotels are anywhere from $250 to $4000 a night depending on where you would like to stay.
Bear Lake is a beautiful place within the valleys of the mountains. You can either hike all the way there or take a bus to shorten the hike by about half. There are trails all around the lake that can take you up to the peaks of the mountains. It is about a half an hour drive from boulder to get to the park.
The Garden of the Gods is a beautiful park located in Colorado Springs. There are several rocky hills coming out of the ground throughout that park that are very fun to explore and walk around. There are several great views in the Garden of the Gods that show off more of the park.
The Rocky Mountains are the mountain range that takes up about half of Colorado. The Rocky Mountain National Park is a 415 square mile area that you can explore to see some excellent views. This National Park shows off the best things of the Rocky Mountains, including things such as Bear Lake, Alberta Falls, etc.