Clear Creek History Park, Golden (always free)
Clear Creek History Park in downtown Golden is now free to walk through, sunrise to sunset every day.
Creek at the Peak Rafting Festival
The Creek at the Peak raft and kayak race takes place on June 23rd, 2012 and provides a great opportunity to watch rafters and kayakers compete for prizes while supporting a great cause. Come check out the race and the after race festival in Idaho Springs on Saturday June 23rd. The festival takes place on the east side of the Springs at the ball fields. The race finishes just west of Idaho Springs and begins in Lawson.
The festival begins at noon and will feature live music, food from local restaurants, and Idaho Springs' famous Tommyknocker beer!
When: Saturday June 23rd, 2012.
The festival begins around noon and continues through the evening.
The races begin at 5pm and will probably finish around 7:30pm.
Where: Idaho Springs at the ball fields on the east side of town.
For all the details, check the Creek at the Peak site: 
Pueblo Chile Festival
The Pueblo Chile & Frijoles Festival in Southeast Colorado is guaranteed to burn your eyes with fun! Besides being overcome with tears in the chili roasting area, you will find a diverse selection of music and dance performances as well as local vendors.
The Boulder Creek Festival on Memorial Day Weekend
The Boulder Creek Festival takes place every Memorial Day weekend in Boulder along Boulder Creek, and features great free music, dancing, rides for the kids, and other entertainment. This is one of the best festivals of the year, and a great thing to do on Memorial Day weekend.
2017 National Park Free Days
The National Park Service offers free entrance to all National Parks a few times each year. This is a great way to explore our beautiful Colorado park lands.
Colorado Free Fishing Weekend (First Weekend in June)
On the first weekend of June each year, Colorado waives fishing license requirements. This is a great chance to grab your gear out of storage and take the family to a nearby lake or stream for some serious trout fishing!
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.
Deprecated: Methods with the same name as their class will not be constructors in a future version of PHP; Zebra_Image has a deprecated constructor in /home/ec2-user/www/public_html/freeindenver/components/com_jem/classes/Zebra_Image.php on line 46
The Littleton History Museum (always free)
The Littleton Museum is a 14 acre indoor and outdoor history museum depicting Colorado pioneer history. Two historic farm sites featuring a schoolhouse and blacksmith shop bring history to life in a way that consistently rates this museum as one of the top living history museums in the United States.
Children's Museum of Denver Free Days (first Tuesday monthly, 4-8pm)
One of the best free Denver attractions for kids, the Children's Museum of Denver's free day takes place from 4pm to 8pm on the first Tuesday of every month, known as Target Tuesdays.
National Center for Atmospheric Research, Boulder (always free)
The National Center for Atmospheric Research (NCAR) has created a beautiful nature preserve on their property on Table Mesa Drive in Boulder, at the base of the Flatirons.
Willie G's Denver Happy Hour (Downtown Denver)
Willie G's is a great place to have a happy hour snack and a cocktail in the middle of the 16th Street Mall in downtown Denver. The street facing patio allows diners to relax with a drink and watch Denver tourists and businesspeople pass by.
Aurora History Museum (always free)
The Aurora History Museum is free and open every day except Monday and certain holidays. There is a permanent display of Aurora history as well as changing displays. This is a great Denver area free attraction, where you can gain a perspective on the real Colorado and the early days of settling this landscape.
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.