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Boulder-Denver City Nature Challenge
Boulder-Denver City Nature Challenge
​​​​​​​​​​​​​​​​Great Horned Own

iNaturalist City Nature Cha​​llenge 2018​

Boulder and Denver are taking part in the 2018 City Nature Challenge, an international effort to find and document plants and wildlife in cities across the globe. Cities are competing against each other to see who can make the most observations of nature, who can find the most species, and who can engage the most people.

The City Nature Challenge is organized by the California Academy of Sciences​ and the Natural History Museum of Los Angeles County

How to Participate

2018 City Nature Challenge 2018 City Nature Challenge

​​Visit, download the free iNaturalist app from the AppStore or Google Play​ (includes the CPW State Parks NatureFinder), join the Boulder or Denver project, then get outside and start taking pictures of the nature around you. ​

The main City Nature Challenge will take place in two parts: 

From April 27 through 30, Denver and Boulder​​ residents are encouraged to go outside to photograph and identify plants and animals as part of this global competition and help your city win the City Nature Challenge! 

From May 1 - 3, anyone can help identify the photos of plants and wildlife down to the species level. Only the observations with species-level identification will count toward the total!  ​

Join a more intense "BioBlitz" at a State Park:

You can participate in the City Nature Challenge with others at two "BioBlitzes" in Denver-area state parks! What's a BioBlitz? According to Wikipedia, a BioBlitz is defined as "an intense period of biological surveying in an attempt to record all the living species within a designated area. Groups of scientists, naturalists and volunteers conduct an intensive field study over a continuous time period (e.g., usually 24 hours)."

Although CPW does host 24-hour BioBlitzes, the City Nature Challenge BioBlitz is a shorter version designed to get you outside using the iNaturalist app with others. Come join us!

BioBlitz Dates and Times

Your Participation Helps Colorado's Scientists

By participating, you will not only help your city win the competition, you will also be contributing crucial data about Colorado’s unique biodiversity. Scientists can then use this information to make important decisions about how to protect and improve Colorado’s nature.

The iNaturalist app has been an ongoing part of Colorado Parks and Wildlife’s efforts to engage citizen scientists.​

Learn More About the State Parks NatureFinder

Part of the fun of the City Nature Challenge is the simple joy of learning about the nature that exists right outside your front door. Once you've started identifying what's in your yard, you may get the urge to journey even further! CPW's State Parks Nature​Finder (part of iNaturalist) is perfect for those hoping to learn more about and document the wildlife in Colorado's 41 state parks.

Newly Added Virtual Guidebooks for the NatureFinder

The Resource Stewardship Program​ at CPW has developed virtual guidebooks for the NatureFi​​nder to help you more easily identify the species found in Colorado's state parks. Check out the plant and animal guides staff have created to help you on your journey. ​

More About Bird Conservation in Colorado

​2018: Year of the Bird Sandhill Crane in flight.

This year marks the centennial of the Migratory Bird Treaty Act​, the most powerful and important bird-protection law ever passed. In honor of this milestone, nature lovers around the world are joining forces to celebrate 2018 as the "Year of the Bird."

CPW is committed to the conservation of birds and their native habitats. Ensuring the success of migratory birds is an integral part of CPW's mission to protect the wildlife resources of Colorado for current and future generations. Documenting the birds you see in nature is a great way to participate as a citizen scientist and support Yea​r of the Bird​!

Find out more about how CPW is participating in conservation efforts for migratory birds.