Meet the Guides

Hiking Guides | Rock Climbing Guides

Hiking Guide Bios

Jocelyn

Jocelyn has been living and working in Yosemite since 2018, and has been guiding for the Yosemite Mountaineering School since 2024. She is an avid hiker/backpacker but also enjoys climbing in her free time. She loves introducing beginners to the outdoors and you can expect to learn about the history of Yosemite as well as flora and fauna on her outings. One of Jocelyn’s passions is talking about how plants were used for medicinal purposes. She holds a Wilderness First Responder, a Leave No Trace Awareness certification, and is a Certified Interpretive Guide through the National Association for Interpretation.

Cody

Cody has lived in and around Yosemite since 2015, and has guided for the Yosemite Mountaineering School since 2024. He enjoys hiking, climbing, swimming, and spending time with his wife and two cats. Something you can expect on Cody’s hikes is getting off the beaten path as he loves to go off trail. Prior to working at YMS he guided for Wildland Trekking for two years. Cody has a Wilderness First Responder, a Leave No Trace Awareness certification, and is a Certified Interpretive Guide through the National Association for Interpretation.

Dan

Dan, a seasoned hiker from Toronto, Canada, has spent three summers exploring Yosemite’s trails and has hiked extensively in Canada and South America. He has been guiding for the Yosemite Mountaineering School since 2024. He has a bachelor’s degree in biology, chemistry, neuroscience. Dan is fluent in Spanish, so he is able to connect with many people on his hikes. He is a Wilderness First Responder, holds a Leave No Trace Awareness certification, and is a Certified Interpretive Guide through the National Association for Interpretation.

Koob

Koob first came to Yosemite in 2017, and has been guiding for the Yosemite Mountaineering school since 2024. He worked in San Diego as a rock climbing instructor and survival (backpacking) counselor at Camp Nawakwa for kids ages 7-16 prior to coming to Yosemite to work. Some of the recent jobs he has done in the park include Ski Patrol at Badger Pass and working at the Day Care Center in Yosemite Valley. Koob enjoys climbing, running, skiing, juggling, and traveling as well as learning about park information and finding peace and perspective in the outdoors. He is a Wilderness First Responder, holds a Leave No Trace Awareness certification, and is a Certified Interpretive Guide through the National Association for Interpretation.

Kate

Kate first visited Yosemite in 2015 and has been in love ever since. She loves sharing her passion of the outdoors and nature with others. Previous job experience includes being a hiking guide, mountain biking guide and paddle boarding instructor in the Bay Area, as well as being a climbing instructor in Colorado for 2 years. Prior to coming to Yosemite this summer, she worked as a Trail Steward for Access Fund building trails in Indian Creek, Utah. This is her second season living and working in the park, and has guided for Yosemite Mountaineering School since 2024. Kate has her Wilderness First Responder, holds a Leave No Trace Awareness certification, and is a Certified Interpretive Guide through the National Association for Interpretation.

Logan

Logan has been living and working in Yosemite since 2021, and guiding for the Yosemite Mountaineering School since 2024. He has been backpacking since the age of 12 and is able to list the Appalachian Trail as one of his accomplishments. In his free time he enjoys hiking, backpacking, climbing, canyoneering, kayaking, and skiing in his free time. Logan holds a Wilderness First Responder, a Leave No Trace Awareness certification, is a Certified Interpretive Guide through the National Association for Interpretation, is a Level II Ski Instructor through the Canadian Ski Instructors’ Alliance, and is Avalanche I certified.

Rock Climbing Guide Bios

Josh Helling

Josh has been a Yosemite Mountaineering School guide and instructor since 1993. He is a Certified AMGA Rock Guide, Certified PSIA Level III Nordic Ski Instructor, Certified in Rigging for Rescue, Wilderness First Responder, and Certified Interpretive Guide. He has more than 28 ascents of El Capitan and has completed over 70 big wall climbs including first ascent big wall expedition climbs in Greenland, Baffin Island, Antarctica, Alaska, Morocco, and Socotra Island (Yemen). Josh has climbed all over North America with many alpine ascents and ice climbs. He has been a member of Yosemite Search and Rescue and is a professional rigger, photographer, and videographer specializing in natural history and high angle camera rigging. Josh is also a Leave No Trace Trainer.

Nathan Kerr

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

Mark Grundon

Mark has been guiding climbing for the Yosemite Mountaineering School since 2009. He’s an 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.

Josh McClure

Josh is a certified AMGA Rock Guide and has been a Yosemite Mountaineering School guide since 2006. His accomplishments include 30+ ascents of both El Capitan and Half Dome, and more than 100 big wall ascents. Josh has climbed both The Nose and the Salathe Wall on El Capitan together in a single day. He has solo day ascents of The Nose on El Cap in 19 hours and 30 minutes and the Regular N.W. Face of Half dome in 6 hours. He has day link ups of Half Dome and El Cap 17 hours and 20 minutes. 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. His certifications include a B.S. in Natural Resources Management, Certified Interpretive Guide through National Association of Interpretation, is a Wilderness First Responder, and a Leave No Trace Trainer.

Nick Malik

Nick has been guiding since 2012 across North America and for the Yosemite Mountaineering School since 2019. He is an AMGA Certified Rock and Ski Guide, Leave No Trace Master Educator, AMGA Assistant Alpine Guide, Avalanche Level 3 Certified, and a Wilderness First Responder. 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. He has a BS in Cellular and Molecular Biology.



Amber Smith

Amber is an AMGA Assistant Rock, AMGA Apprentice Alpine, and AMGA Apprentice Ski Guide as well as an AMGA Single Pitch Instructor. Amber has been guiding for Yosemite Mountaineering School since 2022, and has guided alpine rock and glacier mountaineering objectives in Washington’s North Cascades, as well as crack climbs in the Utah desert since 2016. During the winter months she teaches avalanche education courses in Grand Teton National Park. She is also an Avalanche AIARE Course Instructor, Wilderness First Responder, and Leave No Trace Trainer. Amber graduated with a degree in Geographic Information Systems (GIS) and wrote her undergraduate thesis on what she calls “Feminist Outdoor Leadership: A guide to facilitation strategies for inclusion and participant empowerment in outdoor adventure.” She looks forward to exploring the mountains with you!

Paul Koubek

Paul began guiding in 1996 and is an IFMGA Certified American Mountain Guide with extensive international guiding experience. As an El Capitan guide, he has many one-day ascents of El Cap to his name. He is a former Yosemite Search and Rescue team member, a Denali Lead Guide (12 summits), a Lead Guide on Rainier (10 summits in 10 attempts while guiding in 2018), and a Lead Guide on Aconcogua and Carstensz Pyramid. Paul works for the U.S. Antarctic Program as a mountaineer and Search and Rescue team member. He’s a graduate of the Search and Rescue Institute of New Zealand (SARINZ) in vertical rescue training. Has guided and climbed in Alaska, India, Patagonia, Thailand, Mexico, New Zealand, Canada, and Antarctica with 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. He holds Wilderness First Responder and Leave No Trace Trainer Certifications, as well as being an AMGA certified Rock, Alpine, and Ski guide. 

James Gustafson

Having been born and raised in Alaska, James has a great appreciation for the outdoors. He has been guiding since 2011 in Alaska, Colorado, Utah, Nevada, and California and has been guiding for the Yosemite Mountaineering School since 2018. His favorite type of climbing is long alpine rock objectives. In the off season James can be found traveling around the US guiding rock, ice climbing, and spending his personal time in the mountains. James is an AMGA Certified Rock Guide, Wilderness First Responder and Leave No Trace Trainer.

Jake Squier

Jake is an AMGA Certified Rock Guide, Wilderness EMT, and Leave No Trace Trainer. He has been guiding since 2015 and has been guiding climbing for the Yosemite Mountaineering School since 2022. He has worked in the High Sierra, Joshua Tree, Yosemite, and as far as Vietnam and China. Prior to joining YMS, Jake worked for the Yosemite Search and Rescue team and Mammoth Mountain Ski Patrol. Jake’s experience with big wall climbs in Yosemite Valley include multiple routes on El Capitan, Half Dome, Mount Watkins, Leaning Tower, and Washington Column. He has also climbed many free routes on the granite domes of Tuolumne Meadows. Sport and trad climbing route accomplishments extend into the 5.13 range. Jake loves teaching and sharing his passion for rock climbing with his clients.

Benton Mitchell

Benton is a Certified AMGA Rock Guide, Apprentice Alpine Guide, and Wilderness First Responder with a degree in Adventure Education. He has been guiding for the Yosemite Mountaineering School since 2022. Originally from Pennsylvania, Benton has been climbing since 2015 and has climbed all over the country as well as in Israel. He has hiked the Appalachian Trail as well as the Pacific Crest trail and has guided in areas including Zion National Park, Yosemite National Park, and the surrounding Sierra Nevada Mountain Range. His climbing resume includes El Capitan routes and other big walls, as well as many free climbing routes. His passion is finding the balance between adventure and challenge, and mentoring people with climbing by sharing the joy that it can bring.

Drew Megura

Drew is an AMGA Assistant Rock Guide and passed the Aspirant Exam, and Certified Single Pitch Instructor. He has been guiding for the Yosemite Mountaineering School since 2022. He has a bachelor’s degree in Physics as well as a Wilderness First Responder. Prior to guiding in Yosemite, Drew was a climbing guide and instructor in Acadia National Park, Maine. He has spent a lot of time climbing long routes in the Red Rocks (Nevada), Cochise Stronghold (Arizona), Wind River Range (Wyoming), Rocky Mountain National Park (Colorado), Black Canyon of Gunnison (Colorado), and El Dorado Canyon (Colorado). Drew has climbed multiple big wall routes in Yosemite including routes on El Capitan. Drew is a welcoming and patient guide that enjoys sharing safety information with Yosemite National Park visitors.

Chase Colley

Chase is an AMGA Assistant Rock guide and has passed the Aspirant Exam. He is also a Wilderness First Responder, and a Leave No Trace Master Educator. He’s been guiding for the Yosemite Mountaineering School since 2022. He has a Bachelor of Science degree focused on Therapeutic Recreation and has worked as an adaptive climbing guide, wilderness therapy leader, and navigation and primitive skills instructor. Chase came to Yosemite in 2018 and has climbed some of Yosemite’s big walls, including El Capitan. He enjoys moving over stone on long classic free climbs in Yosemite Valley, Tuolumne Meadows, and the High Sierra. During the winters Chase can be found climbing adventure routes in the San Juans of Colorado and desert towers in Southwest Utah.

Glen Young

Glen is an AMGA certified rock guide who has passed the AMGA Advanced Alpine Guide Course and Aspirant Exam. He has been guiding since 2002, and has guided and climbed extensively around the world, including in the Himalayas, Andes, Southern Alps of New Zealand, Canadian Rockies, Cascades, Rockies of the United States, Sierra Madre of Mexico, and Sierra Nevada. Significant guiding has included AmaDablam, Kyajo Ri, Kangchung Shar, and dozens of 20,000ft peaks in Nepal. In North America Glen has guided many Grade IV and V rock and alpine routes such as the Becky-Chouinard in the Bugaboos, North Face of Mt. Shuksan in the Cascades, North Ridge of Mt. Stuart in the Enchantments, and Resolution Arete in Red Rocks. He has also guided ice and mixed climbing in and around Ouray, CO. Glen has been climbing in Yosemite since 2007 and has experience on most of the major features including El Cap, Half Dome, Leaning Tower, Washington Column, and others. He is a Leave No Trace Master Educator and a Wilderness First Responder with a Master’s in Park, Recreation, and Tourism Management from Lincoln University in New Zealand. In his free-time Glen runs a non-profit in Nepal with Karma Gelyjen Sherpa that provides training to Nepalese mountain guides.

Lance Colley

Lance grew up climbing and mountaineering in the North Cascades where he climbed and guided Mt. Rainier 26 times as well as many other. He has also climbed long, committing alpine rock and ice routes during multiple trips to Alaska, Patagonia, and Canada. As a dedicated big wall climber, Lance has a climbed El Capitan more than 30 times with multiple El Cap speed records. Familiar with the Yosemite landscape, he has climbed over 200 other Yosemite rock climbs. He has a B.S. in Earth and Space Sciences and has contributed to many scientific field studies on the vertical walls of Yosemite National Park. Lance is also able to combine his experience as a Yosemite Search and Rescue Technician, and volunteer Wilderness Patrol Ranger into local decision making that helps him support his clients as a local, professional climbing guide. Lance is an AMGA Assistant Rock Guide and passed the Aspirant Exam, Wilderness First Responder, has completed level 1 & 2 avalanche courses, Advanced Technical Ropes course for rescue, Swiftwater & Flood Rescue Technician, and is a Leave No Trace Trainer.

Tavish Hansen

Tavish is an AMGA Certified Rock Guide, Apprentice Alpine Guide and Ice Instructor, Wilderness First Responder and EMT, Leave No Trace Trainer, and has taken a Professional Level 1 Avalanche Course. While growing up in Seattle Washington, Tavish loved being outdoors. In High School, he learned how to climb at Smith Rock, Index, Leav­en­worth, and the moun­tains of the Cas­cades. Later, Tavish found a pas­sion for teach­ing climb­ing skills and shar­ing expe­ri­ences in the moun­tains with oth­ers. Since 2020, Tavish has been guiding and instructing alpine rock, ice climbing, and glacier travel, and mountaineering in the Cascades. He has traveled and climbed throughout the Western US in search of great climbs, beautiful places, and amazing people to share them with. Tavish has spent several seasons climbing Yosemite Valley’s classic climbs and big walls, including free and speed ascents on El Capitan. Tavish values providing patience, adaptability, and unwavering encouragement to support people’s goals.

Thomas Bukowski

Thomas is an AMGA Certified Rock Guide and Single Pitch Instructor, Wilderness First Responder, and the co-author of a comprehensive climbing guidebook focused on the granite peaks, and domes of Yosemite’s Tuolumne Meadows area. Thomas grew up in Hong Kong, then he discovered rock climbing in high school while living in Norway. Since then, he spent almost two decades climbing in Yosemite, the Sierra Nevada mountain range, and western U.S. Thomas has completed climbing expeditions in Alaska, Baffin Island, the Karakoram, and Patagonia. Before becoming a climbing guide, Thomas climbed as much as they could while working in software startups and global health in San Francisco. Thomas goes by he or they pronouns. They are stoked to share the joys and challenges of the vertical world with you!

Mik Metzler

Mik is originally from the Pacific Northwest and is certified as an AMGA Aprentice Rock Guide, AIAIRE Avalanche Pro 1, Leave No Trace Trainer, and Wilderness First Responder. Mik enjoys sharing wilderness experiences through ski mountaineering, alpine climbing, and big wall climbing. He has climbed and skied in the Alaska Range, throughout the continental US, French Alps, Lyngen Alps, Caucasus, and Canadian Rockies. Some of Mik’s favorite days in the mountains include climbing The Shield on El Capitan, The Nose in a Day, skiing the Rond and Capucin in Chamonix, and climbing Mt. Huntington’s West Face Couloir. Mik has worked on scientific research and conservation projects in the Pacific Northwest, Mojave desert, and Antarctica. He has a BS degree in Supply Chain Logistics and a minor in Ecology.