About Our Xtreme Hike

Join us this year as we take on the trails of Mammoth Lakes, California for a three-day weekend adventure! Participants will embark on a journey through the beautiful Eastern Sierra Nevada Mountains as they raise funds and awareness for cystic fibrosis. As John Muir once said, Of all the mountain ranges I have climbed, I like the Sierra Nevada the best

ALL LEVELS OF HIKERS ARE WELCOME! Hikers have the option to choose from the following trail options below: 


To help you choose, please view the Trail Descriptions and the three trail maps.

Can’t make the in-person hike? Join us as a virtual hiker and train with the other Xtreme Hikers leading up to the event! You can participate virtually from anywhere in the world and participate in the Xtreme Hike Training Challenge!


  1. Register:  Choose your participation. Join as an Individual Hiker, a Team Leader, or Join a Team. You can also register as a Virtual Hiker
  2. Recruit:: Reach out to your friends, family, and co-workers and ask them to join your team. They can join your team and hike in-person on Saturday, October 8thor they can hike virtually from their local area..
  3. Take the Challenge! Join our 3-month Training Challenge and compete for top prizes and overall grand prizes. The Training Challenge starts July 16th and ends October 8th.  Once registered for the event, you will receive a link to join our private OC Xtreme Hike Strava club, where you will compete with other hikers to rack up the most mileage and most elevation gained!
  4. Fundraise: Utilize the tools in the Participant Center, the Fight CF mobile app, and fundraise on Facebook to reach your suggested fundraising goal. Create a passion fundraising event by developing a fundraising event through your favorite hobby, activity, or passion. Contact your event lead, Stephanie Chavez, schavez@cff.org, for assistance with fundraising!
  5. Share your journey! It’s all about storytelling and we want to hear your story! Share your story with others on social media and let them know about the journey you are about to embark on. Share why you hike for a cure by posting on Facebook, Twitter, and Instagram.  Make sure to tag us and use the hashtag #XtremeHike to keep the energy and momentum going strong!
Suggested Fundraising Minimum: $2,500

Weekend Timeline:

Friday, October 7th- Arrive in Mammoth Lakes, CA, check-in starts at 4:00pm, then enjoy the pre-event dinner and program that evening.

Saturday, October 8th- Xtreme Hike Day starts at 6:00 AM, then is followed by a celebratory post-hike dinner and awards.

Sunday, October 9th - Celebratory breakfast and send off celebration!

Lodging Details: Coming soon

Questions:  Please reach out to Stephanie Chavez at schavez@cff.org or 949-339-1753

Thank you Sponsors

We want to thank our generous national sponsors - gold national sponsor, AbbVie, and our silver national sponsors, Nestle Health Sciences, Vertex, Gilead, and Genentech. Thank you, American Airlines, our Outstanding Corporate Supporter.

We also want to thank our local sponsors who continue to help advance our mission.


In lieu of cash, we ask that you make all payments/contributions to the CF Foundation with a credit card or check. We accept all major credit cards. Thank you for understanding.

Events may be subject to change at any time, based on health concerns, including concerns based on guidance from the Centers for Disease Control and Prevention and local health officials. In these instances when events are moved to a virtual format, sponsorship benefits may be adjusted to suit the virtual format.