Become a Larimer County Naturalist!
The City Nature Challenge returns this April! Join a worldwide movement to document nature and help fight biodiversity loss! Every observation you make of WILD nature in Larimer County is a data point that helps scientists and researchers understand and protect nature for all.
This post will tell you everything you need to know – from how-to-play to local City Nature Challenge events.
In short:
City Nature Challenge is a four-day event from April 24-27. Part friendly competition and part collaborative effort, cities all over the world vie to see who can get the most observations uploaded to iNaturalist in just one weekend. Anyone can participate by uploading observations of wild animals, bugs, fungus, or plants found in Larimer County!
See the bottom of this post for a list of local City Nature Challenge events.
In long:
What is City Nature Challenge?
The City Nature Challenge (CNC) is an annual four-day nature census in which participants
around the world use document nature in their neighborhoods. This data help scientists understand
and protect nature worldwide. Started in 2016 as a friendly competition between Los Angeles and San Francisco,
the CNC has grown into an international event. The goal is for cities to collaborate to find species, collect observations,
and connect communities to nature. The Community Science teams at the California Academy of
Sciences (CAS) and the Natural History Museum of Los Angeles County (NHM) make up the
Global Organizing Team.
What is iNaturalist?
iNaturalist is a platform that anyone can use. You can upload pictures or sound clips of species you’ve observed, then the iNaturalist community helps identify those species. Once an observation has been identified, it’s uploaded into databases that scientists use for biodiversity and other ecological studies. It’s a way we can all help contribute to better understanding our local ecosystem!
iNaturalist is the platform Larimer County will be using for our City Nature Challenge observations — any observations made to iNaturalist from within Larimer County during the challenge will automatically count toward Larimer County’s score! You can download the app for free or visit inaturalist.org to use the browser version.
How to Play
Participating in City Nature Challenge is as easy as 1-2-3!
- Observe
From April 24 – 27, 2026, get outside and take photos or record sounds of nature where you live. Look for WILD plants, animals, fungi, etc. (“wild” means it was not put there by people and is not being taken care of by people.) Take a close look at the plants around you. Are there any insects or spiders on them? How many different types of birds can you find in your local park? Put on your nature eyes and see Larimer County in a whole new way!
- Upload
Download the iNaturalist app or create an account on inaturalist.org, and upload your observations. Be sure to include a rough location and time of day.
- Identify
From April 28-May 10 help identify observations that have been uploaded in the Larimer County City Nature Challenge project! Even if the best you can tell is whether it’s an animal or plant, everyone can help narrow IDs down and get us closer to a species ID!
Two Ways To Play:
- Observer — Get outside anywhere within Larimer County from April 24-27 and make observations in nature. Upload your observations to iNaturalist to have them contribute toward the Larimer County City Nature Challenge AND contribute to ongoing biodiversity research!
- Identifier — Keep an eye on the Larimer County City Nature Challenge project page on iNaturalist and help identify observations that are uploaded. You don’t need any prior knowledge or expertise to be an identifier; even narrowing an observation down to “animal” or “plant” helps!
Local City Nature Challenge Events
City Nature Challenge can be enjoyed on your own or with others. Here’s how you can participate:
City Nature Challenge Orientation Sessions – Hosted by Loveland Public Library and Loveland Open Lands and Trails 4/11 and 4/21
11:30-1:00 at the Gertrude Scott Meeting Room in Loveland Public Library, 300 N. Adams Ave, Loveland
The City Nature Challenge, April 24-27, is a friendly, global quest to see which city can document the most species in support of scientific research and biodiversity conservation. This is your chance to become a citizen scientist, let’s see what we can find!
Come to this orientation session in advance of the event to learn more. Open Lands & Trails staff will first discuss how to use the iNaturalist app and make quality observations in the Gertrude Scott Room. Then we’ll head outdoors to the Civic Center Park to practice.
Registration Link
How to Use iNaturalist – Hosted by Larimer County Natural Resources 4/24
9-11am at the Larimer County Natural Resources Admin Offices, 1800 S County Rd 31, Loveland.
Using iNaturalist, participants will learn key features of plants and animals and contribute to the body of crowd-sourced scientific knowledge that is iNaturalist. All observations made in Larimer County will contribute towards the annual City Nature Challenge.
Registration Link
Bio Blitz — Hosted by Loveland Open Lands and Trails 4/24-4/27
From April 24-27, document as many wild species as possible using iNaturalist. Participate on your own or join OL&T staff and volunteers for assistance at selected Natural Areas. Check the Open Lands Calendar for details coming soon, on dates and locations to join Open Lands & Trails on-site.
Pineridge Banding Station — Hosted by Bird Conservancy of the Rockies 4/25
7:30-8:30 or 8:30-9:30 at the Pineridge Natural Area Banding Station, 3502 CR 42C, Fort Collins
Migration is a magical time of year! Join us for a unique opportunity to experience science in action and observe a wildlife biologist banding and collecting important scientific data on live, migrating birds. The data collected gives us insight to many aspects of avian life history and can be used to inform conservation decisions.
This program is provided at no cost to participants due to generous support from donors, but registration is required for all individuals and groups. Groups are limited to 15 people per one hour time slot.
Registration Link
City Nature Challenge ID Party! — Hosted by Fort Collins Museum of Discovery 5/2
2:00-4:00 at Fort Collins Museum of Discovery, 408 Mason Ct, Fort Collins
Now that City Nature Challenge is over, the real work begins. All of our amazing observations of local nature can only assist with biodiversity research once they’ve been identified! Join us at the museum to meet up with other City Nature Challenge Participants. You’ll learn a bit about how to ID observations in iNaturalist and do your part for ongoing biodiversity research!
No wildlife knowledge or expertise required.
Registration Link
City Nature Challenge ID Party! — Hosted by Loveland Public Library and Loveland Open Lands and Trails 5/2
12:00-2:00 at the Gertrude Scott Meeting Room in the Loveland Public Library, 300 N. Adams Ave, Loveland
Join other nature lovers for a fun ID Party to help correctly identify as many observations as possible. Instructions and snacks will be provided. See the Library Calendar for details.
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