City Nature Challenge 2026: Colorado West Slope

The City Nature Challenge is a global project for people, cities, and regions worldwide to collaborate and explore and document nature annually in April. This event is all about getting outside and recording any wild plants, animals, mushrooms, insects, or other wild species you observe.

Anyone with a smartphone, and the free iNaturalist app, can participate. Download the app, create an account, find some local nature (wild only, not pets or garden plants), take pictures, and share these pictures (aka: "observations") to iNaturalist. Any observation made with the iNaturalist app and recorded during the 4 days of the CNC (Apr 24-27) in the 22 Colorado counties west of the Continental Divide will be counted (see map on event website).

Why join in? The natural world is always changing, so by taking part, you will help document all the species living among us right now. In your neighborhood, in your local park, and on your favorite trail or campsite in western Colorado. It's fun for individuals, families, and groups. It's educational - you can learn about the organisms you observe from the iNaturalist app. And this information contributes to conservation knowledge of our local and global ecosystems.

During the 2025 event, over 200 people contributed over 3,200 observations and recorded 819 species of animals, plants, insects, and more, in western Colorado. Globally, 103,000 people in 669 cities and regions made over 3.3 million observations and recorded over 73,000 species.

For 2026, we hope to double the number of people participating in western Colorado. Your participation will help us reach this goal.

Participate as much, or as little, as you want. Each observation is important. You do not have to officially "join" the event to participate - just upload your observations made during the 4 days of the event to iNaturalist and your efforts will be counted. (You have a week after the end of the event to get all your observations uploaded.)

Grab your phone, upload the iNaturalist app, head outside, be observant, and take pictures of any wild animals, plants, or other organisms you find interesting.

Repeat.