Meet the Guides

Hiking Guides | Rock Climbing Guides

Hiking Guide Bios

Andrew Fischer

Andrew has been a Yosemite resident and park employee since 2014 and has been a YMS Hiking Guide since 2018. He is a seasoned backpacker, having well over a hundred nights out in Yosemite both solo and with groups, and has guided backpacking trips over a week-long for YMS. Andrew is a naturalist and loves to teach about Yosemite’s natural resources, ecology, geology, and history. He specializes in equipping people with the necessary skills to navigate the wilderness safely while leaving a minimal footprint on this beautiful National Park. Andrew has volunteered for the National Park Service Wilderness Department in the winter where he skied Yosemite’s backcountry ski trails making sure the trail blazes and signage were in-tact, issuing Wilderness Permits, and assisting with missing person searches. Andrew holds a current Wilderness First Responder since 2015, is a Leave No Trace Trainer, and is an NAI Certified Interpretive Guide.

Nick Castillo

Born and raised in Southern California, Nick grew up hiking and fishing in the Eastern Sierra every summer with his family. It was in these mountains that he developed a passion for the outdoors at a young age. After studying philosophy at California State University, Fullerton, and a brief stint in sales, Nick decided to pursue his passion for outdoor adventure instead and moved to Yosemite Valley in 2018. He loves sharing his knowledge and passion of the outdoors and Yosemite with first time visitors and hikers of all abilities. His favorite things to talk about on trail are Yosemite's history and wildlife, living in the mountains, and wilderness safety. Beside hiking and backpacking Nick also loves climbing, traveling, trail running, body surfing, diving, pizza, breakfast burritos, and a good book every now and then. Nick has trained with the Sierra Club in their Wilderness Travel Course, holds a current Wilderness First Responder, is an NAI Certified Interpretive Guide, and has been guiding with YMS since 2019.

Connor Gibson

Connor has been living, working, and exploring the Yosemite Wilderness since 2017 and has been a YMS Hiking Guide since 2021. As a former competitive swim team and climbing team coach, he loves to teach and share his knowledge and passion with others. Some things Connor likes to teach in his guided hikes are flora and fauna identification as well as skills to help you explore the outdoors in a safer way, while minimizing your footprint on beautiful Yosemite. He loves to get people off-trail and share some of the unique Yosemite backcountry. Connor has held a Wilderness First Responder certification since 2016, is a Leave No Trace Trainer, and is an NAI Certified Interpretive Guide.

Britain Andrew

Britain has been working and living in Yosemite since 2012. He has experience as an Interpretive Guide for the Yosemite Hospitality Interpretive Department where he led hikes and tours packed with information about Yosemite’s history, ecology, geology, and natural and cultural resources. He’s also worked as a Naturalist Guide for the Yosemite Conservancy where he led similar programs. He volunteered for the National Park Service Wildlife Department as a Photo Processor processing photo data from a large-scale grid of motion activated cameras tracking wildlife such as mountain lions, Pacific fishers, and Sierra Nevada red foxes. He has been a YMS Hiking Guide since 2022, holds a current Wilderness First Responder, is Leave No Trace Certified, and is an NAI Certified Interpretive Guide.

Joe Morgan

Joe Morgan has been working in outdoor recreation, education, and social services since 2010. From Akron, Ohio, Joe has worked with people in the outdoors from the mountains of North Carolina to the high deserts of Southwest Utah. After spending some time solo backpacking around Patagonia, Joe moved to Yosemite in 2015 for a season then finally settled here again in 2021 with the goal to be a hiking guide. With that dream fulfilled now, Joe is excited to share with you his knowledge of the natural and social history of Yosemite while soaking in some of the most excellent views in North America. Joe has his B.A. in Psychology, holds a current Wilderness
First Responder, is Leave No Trace certified, and is an NAI Certified Interpretive Guide. He is also a volunteer facilitator for the Yosemite Wellness Coalition. In his free time Joe loves long runs on high country trails and climbing a good splitter crack.

Tammy Bergstrom

Tammy started hiking in the Los Padres National Forest and Santa Monica Mountains in Southern California over 10 years ago and has been doing it voraciously ever since. Before coming to Yosemite, she was a hiking guide for a Wellness Retreat Center in Malibu where she helped people achieve their fitness goals while finding peace and balance in nature. She loves sharing her passion of the outdoors (especially botany and wildlife) with anyone who wants to listen. In her free time, she likes to write about health topics, pan for gold, read, swim, practice photography, climb, hike, backpack, and learn new things. She has lived and worked in Yosemite since 2021 and has been a YMS hiking guide since 2022. She holds a current Wilderness First Responder, is a Leave No Trace Trainer, and is an NAI Certified Interpretive Guide.

Rock Climbing Guide Bios

Josh Helling

YMS guide since 1993. Certified AMGA rock guide, certified PSIA Nordic ski instructor, Rigging For Rescue certified, Wilderness First Responder. More than 26 ascents of El Capitan, and 70+ big wall climbs. First ascent big wall expedition climbs in Greenland, Baffin Island, Antarctica, Morocco, & Socotra Island Yemen. Many alpine ascents, and ice climbs as well as Yosemite Search and Rescue member. Professional rigger, photographer, videographer specializing in Natural History, and high angle camera rigging with a Canadian Fall Arrest Protection Awareness certificate of completion. Leave No Trace Trainer.

Nate Kerr

YMS climbing guide since 2007. AMGA Certified Rock Guide and has completed the AMGA Alpine Guide Course and AMGA Ski Guide Course. Former Pacific Crest Outward Bound School Instructor, avid rock climber, backcountry skier, and alpine climber on three continents while pursuing adventure and sharing outdoor education with others. Yosemite Cross-Country Ski Guide with an American Avalanche Institute Certification Level I & II. Nate is a Wilderness First Responder and Leave No Trace Trainer.

Mark Grundon

YMS guide since 2009. AMGA Certified Rock Guide, Apprentice Alpine Guide, and SPI Assistant Provider. Mark has been climbing since 1998 and has 13 El Cap ascents. He has guided in Colorado, Alaska, Mexico, and Nepal. Mark is a strong believer in “living the dream”, and following your passions whatever they may be. He currently guides in El Potrero Chico in Mexico in the winter. Mark also has an EMT certification, a Leave No Trace Trainer certification, and a B.A. in Recreation and Environmental Studies.

Aaron Jones

Climbing since 2001, in Yosemite since 2003. Aaron is an AMGA certified Rock Guide. Accomplishments include 40 ascents of El Capitan and over 70+ big wall ascents. Solo ascents of Nose on El Cap in 20 hours and Zodiac route in under 13 hours. Active climber of High Sierra peaks. Extensive alpine experience including solo ascents of Torres del Paine in Chile. Aaron is a Wilderness First Responder and Leave No Trace Trainer.

Miranda Oakley

Miranda has been living, working, and climbing in Yosemite National Park since 2006 and is an AMGA certified Rock Guide. She is a big wall climber and has worked as a guide for an international outdoor recreation company based in China. She has traveled and climbed extensively throughout the United States, Asia, Spain, South and Central America. She earned a B.A. in International Studies with a focus in Latin American and Spanish Language. Miranda loves the backcountry of the Sierra Nevada and shares her knowledge and enthusiasm for the outdoors with her clients. Miranda is a Wilderness First Responder and Leave No Trace Trainer.

Josh McClure

Josh is a certified AMGA certified Rock Guide and has been a Yosemite Mountaineering School guide since 2006. Accomplishments include 30+ ascents of both El Capitan and Half Dome and more than 100 big wall ascents. Josh has climbed both The Nose & the Salathe Wall on El Capitan together in a single day. Solo day ascents of The Nose on El Cap in 19 hours 30 mins and the Regular N.W. Face of Half Dome 6 hours. Day link ups of Half Dome and El Cap 17 hours 20 mins. Josh has extensive alpine experience including ascents of Aconcagua, Fitz Roy, first ascent big wall free climbs and first solo link ups in Patagonia’s Fitz Roy range. Josh has also climbed and trekked in many of the world’s mountain ranges including, the Himalayas, the Andes, the Atlas, the Pyrenees, the Sierra, and the Rockies. Certifications include: B.S. Natural Resources Management, Certified Interpretive Guide through National Association of Interpretation, is a Wilderness First Responder, and Leave No Trace Trainer.

Paul Koubek

Paul is an IFMGA certified American Mountain Guide with extensive international guiding experience who began guiding in 1996. El Capitan guide with many one-day ascents of El Cap to his name. Former Yosemite Search and Rescue Valley team member. Denali Lead Guide (12 summits) also Lead Guide on Rainier (10 summits in 10 attempts while guiding in 2018). Lead Guide on Aconcogua and Carstensz Pyramid. Works for U.S. Antarctic Program as mountaineer and Search and Rescue team member. Graduate: Search and Rescue Institute of New Zealand (SARINZ) vertical rescue training. Has guided and climbed in Alaska, India, Patagonia, Thailand, Mexico, New Zealand, Canada, Antarctica - significant Antarctic traverse experience (4000+ miles). Paul currently serves as an elected member of the Board of Directors for the American Mountain Guide's Association. Wilderness First Responder and Leave No Trace Trainer certifications, as well as AMGA certified Rock, Alpine and Ski guide.

Greg Coit

Greg is a Wilderness First Responder, Leave No Trace Master Educator, and is an AMGA certified Rock Guide. He has worked as a YMS guide since 2011 with multiple guided ascents of El Capitan, Half Dome, Sentinel Rock, and other big walls throughout Yosemite. Greg spends his free time backpacking, skiing, and rock climbing. Greg also enjoys climbing alpine peaks in the Sierra Nevada mountain range. He has a bachelor’s degree in Outdoor Education from the University of New Hampshire; is a graduate from the National Outdoor Leadership School; and has guided rock climbing and backpacking in New England, North Carolina, Washington, and Yosemite.

Allen Higginbotham

Allen climbed his first Yosemite big wall in 2005. Since then he has made ascends on all Yosemite's major walls, but his main passion is teaching. His dedication to sharing his knowledge, helping new climbers improve their skills, and mentoring skilled climbers is why he loves working for Yosemite Mountaineering School. Allen has passed the AMGA Advanced Rock Guide Course and Aspirant Exam making him an AMGA Assistant Rock Guide. Allen is a Wilderness First Responder and Leave No Trace Trainer.

James Gustafson

Born and raised in Alaska, which gave James a great appreciation for the outdoors. He’s been guiding since 2011 in Alaska, Colorado, Utah, Nevada, and California. His favorite type of climbing is long alpine rock objectives. In the off season he can be found traveling around the US, guiding rock and ice climbing, or spending his personal time in the mountains. James has passed the AMGA Advanced Rock Guide and is a Wilderness First Responder and Leave No Trace Trainer.

Camden Clements

Rock climbing since 2001, YMS guide since 2017. Camden is originally from South Carolina and quit his job as a software developer in 2014 to hit the road and enjoy rock climbing around the US and the world. Camden enjoys climbing on Yosemite's big walls like El Capitan but also enjoys other types of climbing like sport climbing, bouldering, and mountaineering. He has climbed both the Salathe Wall and The Nose on El Capitan together in a single day. He has also climbed Half Dome and El Capitan in the same day. Camden is technically gifted with vast amounts of Yosemite climbing experience. He is soft spoken, patient, and enjoys helping others realize and achieve their climbing goals as well. Camden is an active member of Yosemite Search and Rescue, is a Wilderness First Responder, and has at least one speed record on El Capitan. Leave No Trace Trainer

Jake Ramsey

Jake is a Certified AMGA Rock Guide and his background in rock climbing began in the state of Colorado. As an avid ice climber and skier, he explored the Rocky Mountain Range. Climbing sandstone, limestone, and granite inspired Jake to move to Yosemite National Park in 2015. Amongst the granite giants he could focus on long aid routes, difficult free climbs, and Yosemite big walls. Climbing multiple ascents of El Capitan and Half Dome kept Jake busy while working as backpacking and hiking guide where he helped park visitors explore the High Sierra on foot. In 2016 Jake became a Yosemite Mountaineering School climbing guide. Jake is a Wilderness First Responder and Leave No Trace Trainer.

Nick Malik

Nick has been guiding since 2012 across North America. He is an AMGA Certified Rock Guide, Leave No Trace Master Educator, AMGA Assistant Ski Guide, AMGA Apprentice Alpine Guide, and Avalanche level 3 certified. Nick spends winters ski guiding in Jackson Hole and climbs in the desert during his time off. He has climbed over 600 days in Indian Creek including the establishment of many new routes. His climbing resume includes numerous free ascents of 5.13 cracks, onsighting up to 5.12+ trad, and many one day ascents of El Capitan. BS Cellular & Molecular Biology.

Keith Neas

Keith is originally from Anchorage, Alaska and he began climbing in 2010. He traveled and climbed on an extended road trip and eventually made his way south to Yosemite in 2014 where he climbed multiple ascents of Half Dome and El Capitan. His true passion is free climbing, but he also enjoys big wall climbing and high-country domes. Keith has completed the AMGA Rock Guide Course and is pursuing further AMGA certification and began guiding for YMS in 2018. When not climbing, you can find Keith out riding his mountain bike, or fishing the streams of Yosemite. Leave No Trace Trainer.