Morrison Nature Center at Star K Ranch, Aurora (always free)
The beautiful Morrison Nature Center is a free park in Aurora, Colorado that is definitely worth checking out when you are in the area.
Snowmass Summer Concerts
On summer Thursdays and Fridays the laid back atmosphere of Snowmass Colorado comes alive with their free Snowmass Village Summer Concerts. The music, set up on a Snowmass ski run stage near the upper village, is loud and wild.
When:
Summer Thursdays (and sometimes Fridays) from 6:15 to 8:30pm.
Where:
Snowmass upper village.
Schedule:
The 2013 Snowmass Village Free Summer Concert schedule is as follows:
June 20: Freddy Jones
June 27: The Dunwells
Friday July 5: CJ Chenier
July 11: The Revivalists
July 18: Mountain Standard Time
July 25: J.Boog
August 1: Tab Benoit
August 8: Nigel Hall
August 15: Robert Walters
More Info from the Aspen Snowmass web site: 
Denver Center for the Performing Arts ($10 tickets)
The Denver Center for the Performing Arts offers a limited number of $10 tickets, every Tuesday morning, for shows coming later in the week.
Manitou Springs Great Fruitcake Toss Festival (annually in January)
Colorado is known for it's goofy festivals and the Great Fruitcake Toss is certainly one of the headliners. This Manitou Springs tradition is held every year after the holidays in an effort to dispose of certain unwanted confections you may have acquired.
Some people prefer to launch their cakes by hand but many choose to build elaborate contraptions to give their fruitcakes the send off they deserve. There are various cake launching categories as well as competitions for the best and prettiest fruit cakes.
When:
The 2014 Great Fruitcake Toss festival has been cancelled. Hopefully it will be back in 2015.
Where:
In Manitou Springs at the Manitou Springs High School track.
401 El Monte Place
Manitou Springs, CO 80829.
Old Globeville Days and the Orthodox Food Festival (annually in July)
The Old Globeville Days Orthodox Food Festival celebrates Denver's international immigrant heritage with a diverse selection of free entertainment and international food. The music features outstanding performers of diverse folk heritage including an amazing Celtic performance. The incredible food selection is sample sized and you purchase tickets to try the samples. One of the best things to do in Denver on a warm mid-July weekend.
Garden of the Gods, Colorado Springs (always free)
Garden of the Gods in Colorado Springs is probably the most beautiful small park in the state. Paved trails make it easy to wander around and check out the amazing cliffs and spires. Picnic areas, paved and unpaved hiking trails, horseback riding, a trading post, and a visitor's center with amazing views; Garden of the Gods is a great place to spend a day.
Jefferson County Open Space Parks (always free)
Jefferson County Open Space Parks are probably the best park value in Colorado. A tremendous variety of parks and activities, such as hiking, mountain biking, climbing, and geocaching, all free to anyone.
Here is a list of their parks, maps, details, etc...
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University of Colorado Museum of Natural History at Boulder (always free)
The University of Colorado Museum of Natural History is a free natural history museum on the CU Boulder campus. They have excellent changing exhibits, a dinosaur section, and an extensive bird display. A small donation is requested to help keep the museum open and free. This is a fun small natural history museum for adults and curious kids.
When:
Monday - Friday 9am - 5pm
Saturday 9am - 4pm
Sunday 10am - 4pm
Where:
The Henderson Building on the CU-Boulder campus, between 15th and 16th streets east of Broadway.
For details check their web site:
McLoughlin's Restaurant and Bar (Downtown Denver)
McLoughlin's is one of my go-to places when I'm craving happy hour specials in downtown Denver.
Budweiser Tour in Fort Collins (always free)
The Budweiser tour in Fort Collins ranks right up there with the Coors tour in the battle of the Colorado beer tours. Anheuser-Busch has offered very professional and detailed tours of their Fort Collins brewery for many years and the popularity continues to grow.
Irish Snug Denver Happy Hour (Capitol Hill)
Happy hour at the Irish Snug just south of Denver offers cheap, quality food and more than affordable drinks. Their happy hour menu is offered every day from 3-7 and 10-12. A diner will encounter traditional Irish fare, such as corned beef sliders and sangers. If you don’t like Irish food, don’t worry. The Irish Snug also offers burgers, tex mex and sophisticated American bar food.
Colorado State Capitol Free Tours (Weekdays)
The Colorado State Capital is one of the popular Denver Attractions, not only for the well known '5280 step' but also for the free tours inside.
Why take a Colorado State Capitol tour? I'll give you three reasons:
- The Colorado State Capital building in downtown Denver allows you to watch our state Legislature in action. As more people take an interest in the workings of our government, this is a great opportunity to see firsthand how the system works. The Colorado State Legislature is in session from early January to early May.
- The capitol building itself is awash in history and amazing architecture. It was built using Colorado materials as much as possible, such as Colorado gold for the dome, granite walls from Granite, Colorado, and Colorado's distinctive red onyx throughout the interior.
- The views from the Dome tour are some of the best in Denver!
Location:
Just head for downtown Denver and the 16th Street Mall, you can't miss the gold domed building beyond the southern end of 16th street mall. The steps on the western side are the most popular area to enter as the "1 mile above sea level" markers are there. The civic center park area has become very sketchy, expect to encounter quite a few homeless if you walk through the park.
Visitors to the state capitol are allowed to wander the public areas on their own, or you can take one of several guided tours:
Historical Tours:
All about construction of the building and early Colorado history, as well as some of the more interesting artifacts on display within the building. Reservations are not required unless you have a group of 10 or more. Tours are 45 minutes long and are available weekdays except holidays.
Historical Tour Hours:
10am - 3pm every Monday - Friday
Legislative Tours:
Legislative tours are a popular field trip for Colorado grade school students. When possible, you will make stops in the House and Senate galleries to see the legislature in action. This tour is only for school groups and reservations are required.
Legislative Tour Schedule:
Annually, early January through early May. Reservations are required.
Dome Tours (currently closed):
This tour climbs a long spiral staircase to an indoor observation area with amazing views of Denver.
Dome Tour Hours:
Daily from 9am to 2:30pm. Reservations are required.
Dome tours are currently closed until further notice due to dome renovations.
Mr. Brown's Attic:
This exhibit area illustrates Colorado's history and the legislative process, and includes a hands-on children's area. The attic is open 9am to 3pm on weekdays and reservations are not necessary.
For more information about Colorado State Capitol Tours, visit the Colorado Legislative Council Site:
Ruby Hill Rail Yard
For about 6 weeks each year in January and February, Ruby Hill Park in Denver features a free ski and snowboard park known as Ruby Hill Rail Yard.
Liftopia Ski Discounts
Colorado resorts offering substantial Liftopia ski discounts:
Arapahoe Basin.
Copper Mountain.
Durango.
Loveland.
Monarch Mountain.
Ski Cooper.
Sunlight.
Winter Park.
Some other resorts have discounts on Liftopia that really aren't discounts at all.
Check out Liftopia:
Rentals
If you need to pick up rentals on your way to the mountain, my favorite super cheap rental shop is Maison De Ski in Idaho Springs.