About Us

El Potrero Chico Guides S.A.de C.V. is Owned and Operated by Mark Grundon an AMGA Certified Rock Guide.  We believe in guiding credentials and strive to provide the highest trained guides possible for you in El Potrero Chico.  El Potrero Chico Guides was started by Mark Grundon in 2009 and has been providing quality instruction and guiding for 11 years.

Mark Grundon

Mark has been guiding from Alaska to Colorado for the last 16 years. He also currently spits his time between Yosemite National Park and El Potrero Chico.  He also guides trips on Mexico's volcano Pico de Orizaba. He recently retired from ski patrol after seven winters to follow his deeper passion: climbing. Mark is a strong believer in “living the dream”, and following your passions whatever they may be. Mark enjoys sharing a rope with everyone from Yosemite rock stars to first time climbers. He has guided 7 successful summits of El Capitan. He has made one day ascents of El Cap and Half Dome in Yosemite. Mark has his EMT, a Leave No Trace trainer certification, is an Assistant AMGA Single Pitch Instructor Provider, AMGA Apprentice Alpine Guide, and AMGA Certified Rock Guide.

Heidi Wirtz

 A certified AMGA Rock Guide, is a climber, yogi and philanthropist at heart. She holds a deep love of connecting with nature, sharing her passions and inspiring others to follow their dreams. She has been guiding in the outdoors for over 20 years and has extensive training in the alpine and rock guiding world . Heidi Wirtz is one of the country’s few prominent female adventure climbers. She has been climbing for over twenty five years, letting her passion for adventure and exploration lead her to exotic and remote places around the world. Heidi has pioneered new routes up unclimbed big walls and mountains and pushed the limits of female exploration.  Heidi is founder and owner of an adventure retreat business called Earth Play Retreats (EPR), which combines adventure sports, connection to nature and yoga. Through Earth Play Retreats, she is dedicated to offering her clients a transformational experience that will carry over into her students' everyday lives.

Caden Lightcap

Caden has completed his AMGA Rock Guide Course.  Caden is from Colorado, he has spent the last 8 years traveling and climbing all over the world. Caden also spent 10 years working in the service industry before he became a rock guide. He is committed to safe practices and having lots of fun on the rock. He believes life is a gift and lives everyday with gratitude and stoke. Caden has been guiding for the past 6 years, in the Black Canyon of the Gunnison, on desert towers in Utah and Arizona, and in Eldorado Canyon. Caden is a wilderness first responder and has spent the last several years working with the Black Canyon and Crested Butte Search and Rescue teams.

Pete Fasoldt

Originally hailing from Maine, is a certified AMGA Rock Guide. He has worked as a ski patroller, as first mate on sail boats and as the owner of a rock guiding outfit in Acadia National Park. Pete now works as a rock and alpine guide throughout California's Sierra Nevada from the Lake Tahoe area down into the High Sierra and in Mexico in the winter season. Pete has put up many new routes including a ten pitch 5.12+ route in the nearby La Huasteca Canyon. He has climbed all over the world including ascents of the Trango Towers.

Adam Mitchell

Adam has been guiding in El Potrero Chico for years.  He is an AMGA Assistant Rock Guide and will be taking his exam soon.  He is an AMGA Single Pitch Provider and runs a climbing school in Teexas at Enchanted Rock.