Conejo Open Space Foundation

The Conejo Open Space Foundation is dedicated to helping preserve, promote and protect natural open space through community education and involvement. We support these efforts by fundraising and volunteer engagement.

2025: 30 years of connecting community and nature!

Upcoming Events
The 2025 Conejo Open Space Challenge ends on May 31! (5/28/2025) - There are only a few days left until The Challenge ends this Saturday! That means there's still time to check out two or three trails if you're almost finished, or to cram in all ten if you haven't started. Here are some more great photos submitted by the participants. Over time, you'll notice there's more and more mustard next to the trails. If you would like to join the fun, check out the details on our Conejo Open Space Challenge page! (read more...)
Wildflowers are the subject of our Spring edition of the Four Seasons Photo Contest (3/11/2025) - The subject of the Spring Four Seasons contest is wildflowers. This contest runs until May 31. To enter the contest here are the rules: Every season, we’ll identify a specific item (e.g., “an oak tree”) for you to find within the Conejo Open Space. As long as the object is within COSCA property, it qualifies. Here is a map of the Conejo Open Space trails. After you’ve located an object that matches the challenge description, take a photo of it. Then email us your entry and tell us where in the Conejo Open Space you took it. If you like,… (read more...)
News from COSF (View all the updates.)

Amgen volunteers Watch the video of an Amgen volunteer team haul one ton of trash out of the Arroyo Conejo (5/25/2025) - On May 2, an enthusiastic team of 15 Amgen staffers joined COSCA Rangers Joe and Kari and COSF President Bill Miller and board member Anne Russell for a morning clean-up at the Arroyo Conejo. The video of the work can be seen below. The Amgen group removed about one ton of garbage that included cans and bottles, bicycle parts, gardening… (read more...)
You have just 3 weeks to complete the Conejo Open Space Challenge for 2025! (5/9/2025) - The COS Challenge ends on May 31, a date that is rapidly approaching! Already several dozen people have completed all ten trails. If you would like to qualify for some of the fabulous prizes supplied by the Conejo Open Space Foundation, and Giant Bikes, at the final celebration on June 6, you should put on your hiking boots or riding… (read more...)
2025 Spring COSF Newsletter (4/27/2025) - The spring edition of the Conejo Open Space Foundation newsletter has been posted. In this edition… Environmental Studies Scholarship Winners : New Threat to Conejo Oaks : Neighborhood Coyotes : CRPD  Superintendent Matt Kouba Retires (photo at right) : Winter Photo Contest Winner : And More! View our Spring Conejo Open Space Newsletter.   (read more...)
Third photo gallery from the 2025 Conejo Open Space Challenge (4/23/2025) - There are 5 weeks left in the 2025 Conejo Open Space Challenge. That's plenty of time to get out and explore the 10 Challenge trails, even if you haven't started yet. The great photos are continuing to roll in! Here are some more of them. If you would like to join the fun, check out the details on our Conejo… (read more...)
Forest expert Kim Corella discusses new threat to our Conejo Valley oaks—see her recorded presentation (4/21/2025) - Kim Corella, who is Cal Fire's Forest Pathologist with the Forest Entomology and Pathology Program for Southern California, addressed what could be a slow-moving disaster for our Coast Live Oaks in her Speaker Series talk "Oaks in Peril" on April 16. Having served with Cal Fire for the past 17 years, Corella has witnessed the goldspotted oak borer's path of… (read more...)
Another photo gallery from the 2025 Conejo Open Space Challenge (4/15/2025) - We're now exactly half way through the 2025 Challenge! Here are some more great photos submitted by the enthusiastic participants. If you would like to join the fun, check out the details on our Conejo Open Space Challenge page! (read more...)
Winter photo contest winner is Summer Noble (3/24/2025) - Congratulation to Summer who submitted this photo of acorns that she took on the Spring Canyon Trail. If you would like to enter future contests, here are the rules: Every season, we’ll identify a specific item (e.g., “an oak tree”) for you to find within the Conejo Open Space. As long as the object is within COSCA property, it qualifies.… (read more...)
First photo gallery from the 2025 Conejo Open Space Challenge (3/15/2025) - We're only two weeks into the 2025 Challenge and participants have already submitted dozens of great photos! Here are some of them. If you would like to join the fun, check out the details on our Conejo Open Space Challenge page! (read more...)

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