The City Nature Challenge began in 2016 as a competition between San Francisco and Los Angeles to see which city could document the greatest amount of biodiversity over a weekend in April, using the community science application iNaturalist. Since then, the competition has expanded to hundreds of cities around the world. This year, the City Nature Challenge continues as a “collaboration-meets-friendly-competition.  This worldwide collaborative effort allows people to safely document nature and embrace its healing power.

At USC, the Environmental Studies Program, in partnership with the Environmental Student Assembly, Peaks & Professors, and the Wrigley Institute for Environmental Studies is organizing a CNC project to encourage USC students, staff, and faculty to participate in the City Nature Challenge.

Included here are documents that will help you document species on the weekend of April 26 – April 29, 2024 as part of the City Nature Challenge X USC 2024.  Participants can upload observations anywhere in the world for the CNC, but the USC project will be focused on documenting species in LA County.


Students can sign up for special Peaks and Professors hikes the weekend of the City Nature Challenge.  Keep an eye out on the Peaks and Professors website for the hike signups to open.

Details, tips, and tricks for CNC X USC

Using iNaturalist on your phone

City Nature Challenge X USC 2024 project on iNaturalist

Answers to common questions about the CNC

We urge all participants to carefully follow public health guidelines provided by our local governments, as they are changing in real-time. Individual safety and public health are our utmost priority. Please refer to our COVID-19 FAQ page for more information.