Who We Are


Meet our team

Leadership Team

Peter Mayfield - Executive Director

Peter Mayfield

Peter has been a successful leader, pioneer and innovator in mountain sports programs for the last 27 years.  He has started three innovative businesses: CityRock, Yosemite Guides, and Gateway Mountain Center, through which he has designed and delivered creative and successful outdoor educational programs for thousands of California youth.  Peter has served as Chief Guide for the Yosemite Mountaineering School, and as Chief Examiner for the Professional Ski Instructors Association (Far West). As the founder and General Partner of CityRock Gym, the first large urban climbing gym, Peter was a catalyst for the growth of indoor climbing in North America. As a consultant Peter has designed and developed adventure programs for Disney, Discovery Communications, and Posades Resorts.  As a creative mountaineer Peter has succeeded on first ascents on Yosemite's El Captain and Half Dome, climbed new routes in Peru, Patagonia, and the Alaska Range, and pioneered difficult snow board descents.  In addition, Peter has competed in sport climbing World Cups, Cross Country Skiing US Nationals, and performed for ten years with the aerial dance/climbing troupe, Project Bandaloop.


Melony Vance - Administrative Director

Greg Bernstein

A California native, and daughter of a gold miner, Melony comes to Gateway with a broad and varied background. Prior to moving to Truckee, she was the Development Director at Bear Yuba Land Trust, was the Executive Director of the Yuba Watershed Institute, has worked in the real estate industry in financing, escrow and insurance, been a CPA's full-charge bookkeeper, and owned/operated a bookstore in Southern California. Her skill at juggling many diverse projects, keeping everything organized and operating smoothly makes her ideal as Gateway’s administrative “hub.” Her passion for getting people outdoors into nature – and making sure that every kid gets a chance to experience themselves in the amazing landscape of the Sierra Nevada – are what brought her to work at Gateway. When she isn't deep into spreadsheets, you will find her out hiking, kayaking, rafting, snowshoeing, reading or cooking. She is also a Sierra Club hike leader, was a whitewater rafting guide for Friends of the River, is a massage practitioner, world traveler, and self-proclaimed adventurer of mind, body and spirit.



Greg Bernstein - Director of Operations

Greg Bernstein

As a filmaker, Greg shot documentaries for over two decades. Travelling all over the world, he worked to promote Environmental Justice and Human Rights with numerous organizations including: Greenpeace, The Rainforest Action Network, Amazon Watch, The Sea Shepard Conservation Society, and Project Bandaloop. More recently Greg has been working with 3D Cartography, GIS systems, 3D Printing and robotics. As a Guide/Mentor, he has been active providing embodied peak experiences in nature for youth of all types for many years since pursuing his degree at Prescott College where he studied Wilderness Leadership, Media Arts and Psychology. He recently completed the AMGA Single Pitch Instructors course. Greg believes that increasing eco-literacy, wholistic system-based critical thinking and immersion in nature are critical skills and experiences for people of all ages.



Rob Zimmerman - Whole Hearts Minds and Bodies Program Manager

Rob ZimmermanA nearly life-long student of traditional healing arts, Rob first began healing work as a Reiki practitioner at age 15. During his senior year of high school, he began his work with children as a volunteer for Big Brothers Big Sisters of America. Further pursuing his passion for healing, Rob enrolled at the University of New Hampshire, where he graduated Magna Cum Laude with a B.A. in Psychology and Interpersonal Communications. In his adult years, he has volunteered in numerous settings, including assisting learning-challenged youth at The University of New Hampshire’s Center for Academic Resources, leading meditation workshops for the YMCA, and helping people of all ages one-on-one as a mentor. In the for-profit sector, Rob has many years of experience in operations management, overseeing teams as large as 45 in multi-million dollar enterprises.
When not at work, he is an active skier, cyclist, backpacker, and rock climber.



Rachel Durben -School Programs Director

Rachel Durban

Rachel Durben holds an M.S. in biology from Northern Arizona University, and has extensive research and education experience. Her research interests include riparian, stream and meadow ecology, especially concentrated on species interactions and ecosystem health. Rachel has designed curriculum for students aged 5 through adult, focusing on field-based ecological education and collaboration. She has taught public, charter and home school classes and field lessons, and conducted workshops and trainings for community groups, California State Waterboards staff, and college students, including the UC California Naturalists Program. As Gateway’s School Programs Director and Van Norden Meadow fieldwork coordinator, Rachel is thrilled to unite her passions for science and education, sharing her love of the outdoors and the wonders of nature with people of all ages. Rachel strives to facilitate awareness of our connections - with each other and with the natural environment - through mindfully directed outdoor experiences, constructive communication and deep self-inquiry. When not working with Gateway, you can find Rachel rafting, skiing, hiking, running, traveling, practicing or teaching yoga.



Nancy Minges, M.A., CMP -Wellness Director

Matt Sole

Nancy primarily serves as our Wellness Program Director. She guides students in finding their own voice, discovering new ways to access their innate, deep well-being, and developing a healing relationship with nature. By using their inner experience, she supports students in becoming change agents for themselves and our world. She holds a Master’s Degree in Holistic Health Education from John F. Kennedy University, with emphases in transpersonal and somatic psychology. She has multiple certifications in numerous bodies of work, including Mindful Schools, Gestalt Awareness Practice, Continuum, trauma resolution, massage therapy, and a 20+ yr. certificate of study for teaching all levels of meditation, pranayama, and yoga through the feminine centered approach of Angela Farmer. For years, Nancy taught mindful movement practices at Spirit Rock Meditation Center, and guest taught at Esalen Institute. She currently teaches or assists on retreat, as requested. With a B.A. in Communications, Nancy also assists in various organizational needs for Gateway Mountain Center.



Harris Talsky - Chief Guide

Harris Talsky

Harris has a great passion for the outdoors, which he strives to share with others. He developed his love for the Sierra Nevada mountains while earning a BS degree in Geological Sciences at the University of Southern California. After graduating in 2010, he moved from the beach to the Tahoe area, where he enjoys rock climbing, slacklining, yoga, hiking, and volleyball. Guiding with Gateway Mountain Center has given him the opportunity to share these fun outdoor activities with students, in combination with providing a greater scientific understanding of the world around them. He has volunteered for the Peer Health Exchange by educating at-risk youth about health promotions. He is an AMGA Certified Single Pitch Instructor and loves getting people on rock to challenge their mind, body, and spirit in new ways!






Field Science Team


Sarah Yarnell - Field Science Advisor

Sarah Yarnell

Senior Researcher UCDavis Center for Watershed Sciences

Hydrology, Fluvial Geomorphology and Stream Ecology



Ph.D. in Hydrologic Sciences with an emphasis in Surface Hydrology and Stream Ecology, University of California, Davis, March 2005.

M.S. in Geology with an emphasis in Fluvial Geomorphology, University of California, Davis, September 2000.

B.S. with honors in Environmental Biology and Management and a minor in Geology, University of California, Davis, June 1995.


Professional Background

Sarah is an Associate Project Scientist at the Center for Watershed Sciences. Her studies focus on integrating the traditional fields of hydrology, ecology and geomorphology in the river environment. She is currently conducting research that applies understanding of river ecosystem processes to managed systems in the Sierra Nevada, with a focus on the development and maintenance of riverine habitat under current and future climate conditions. She is a recognized expert in the ecology of the Foothill yellow-legged frog (Rana boylii), a California species of special concern, and she is the first researcher to apply sediment transport and two-dimensional hydrodynamic modeling techniques to the evaluation of instream amphibian habitat. More recently, her experience has expanded to include consultation as a technical expert for various hydroelectric power relicensing projects (Big Creek Project, Desabla-Centerville Project, Middle Fork American Project, Yuba-Bear/Drum-Spaulding Project), where she has work closely with government resource agencies and the private sector to assess the impacts of environmental flows on aquatic biota.


Ryan Peek -Field Science Advisor

Ryan Peek

Research Staff UCDavis Center for Watershed Sciences

Amphibian Ecology and Aquatic Biodiversity










Professional Background

Ryan Peek joined the Center for Watershed Sciences full time in February 2011. He is interested in biological and ecological responses to watershed alteration and aquatic ecosystem health. His research focuses on applied methodologies that can be used to assess resilience of freshwater ecosystems to better inform management responses to climate warming and environmental degradation. . He has worked extensively with sensitive amphibians, including a mountain / sierra yellow-legged frogs (Rana muscosa / sierra) restoration project with the National Park Service, as well as assessment of connectivity and genetic fragmentation of foothill yellow-legged frogs (Rana boylii) in managed rivers in California.  He currently is conducting research that applies modern genetics and river ecosystem processes to assess biodiversity and watershed resilience in managed systems in the Sierra Nevada, with a focus on integrating and maintaining riverine habitat diversity under current and future climate conditions.  His research experience includes extensive analyses of freshwater ecosystems throughout CA and OR, with special focus on hydropower regulation and environmental management of rivers and streams in the Sierra Nevada. He was the field lead and one of the main authors for the Spring Recession Project and has contributed to PISCES, Mountain Meadows, CEC Yuba, and Freshwater Conservation projects. 




Catherine Schnurrenberger -Van Norden Meadow Research Coordinator

Catherine Schnurrenberger

Catherine is a botanist/plant ecologist with a Master’s degree in Hydrology. She grew up in California and is a product of the open spaces of the American west. She started her career in Rangeland management in Northern California branching off into botanical consulting and plant ecology. She is also passionate about travel to different cultures and environments. After leaving college she travelled by bicycle from California to Tierra del Fuego. A love for natural communities at the extremes drew her to work in Alaska studying coastal brown bear habitat and to Patagonia to studying Huemule deer habitat. She is currently raising two boys and enjoying the interface between science, nature and young people. She has worked with various local non-profit organizations in outdoor education, outdoor skills and the natural sciences. Catherine enjoys all manner of outdoor activities that are kind and respectful of the earth.





Rachel Durban -Van Norden Meadow Research Coordinator (See Bio above)






Field Instructor - Guides


Annie Overlin - Education Director/Guide

Annie Overlin

Originally from a family of ranchers, nature lovers, and environmental stewards from Central Colorado Annie thought she’d never leave home. Until a field trip at 18 with Fountain Valley School to Yosemite Valley where she first climbed the Snake Dike route on Half Dome. At the time her family had no idea the effect the perfect granite walls would have, but the following 12 year love affair with rock climbing would only be decelerated by the love for her own family. At 31 she started raising a family of her own, using a real toilet, and working as a plant ecologist and teacher. On the way she started working for Peter Mayfield who shared and helped cultivate her vision of introducing kids to wild landscapes. With Gateway Mountain Center, she has been heavily involved with the kids climbing camps and collaborating with UC Davis developing the curriculum and data collection efforts in Van Norden Meadow. She currently runs a small biological consulting firm and is working on a graduate degree in Restoration Ecology focusing on wetlands. When time permits, she tries to nourish her inner wildness on the granite or snow.


Anna Toso - Education Director/Guide

Anna Toso

Anna started her career in environmental education in 1983 as a farm and wilderness teaching intern at Slide Ranch, eventually becoming the program director for a number of years. Anna has been involved as a naturalist guide, teacher trainer, consultant, and director for a variety of other programs on the coast of California and in the Sierra Nevada, including Yosemite National Institute's Headlands Campus, Sierra Institute's South Lake Tahoe E.E. Program, Elderhostel (coastal programs and in the Sierra Nevada), Trips and Trails, and Gateway Mountain Center. Anna enjoys a hand-on approach to sharing the natural world with people of all ages and abilities.





John Littleton -Guide

John Littleton

John Littleton is a native of Chicago Illinois but has called the Sierra Nevada his home for too many years to mention. He discovered his love of the mountains at an early age while taking family trips out west. He credits these experiences as being the sparks that opened his eyes to the wonders of the outdoors. As a professional outdoor educator John thrives on providing that same opportunity and exposure to his students. When John is not guiding for Gateway, you may find him ski touring or rock climbing in what he calls his "backyard".


Renee Guay - Guide

Renee Guay

Renee is passionate about teaching outdoor and environmental education while inspiring students to find their inner strengths and connect to the natural world. She has ten years experience working with youth in the outdoor industry with various programs throughout the U.S. She received her BA in Interdisciplinary Studies with a concentration in Outdoor Adventure Leadership from Sierra Nevada College. Rock climbing has been the love of her life for the last ten years. Renee has completed the AMGA Single Pitch Instructor course and has competed on the national collegiate level. She spent four years working at the Truckee Donner Recreation Center where she was a recreation leader for teen programs. She also developed and operated a new climbing wall at the recreation center which gave her experience beyond just a climbing instructor. Her favorite place to climb is Thailand where she traveled on a solo adventure. Renee is also a certified Wilderness First Responder and Lifeguard. Yoga, dancing, snowboarding, and nutrition are other passions that she holds sacred. As a Gateway Mountain guide, Renee strives to make a positive impact on students.


Aaron Finely -Guide/Mentor

Aaron Finely

Aaron Finley hails from the state of New Hampshire where he attended Plymouth State University, earning a degree in Social Science Education. His love for the outdoors and passion for working with kids have instilled a desire to connect children to the joys of the outdoors. Aaron has worked at a foster home as a mentor where he often led outdoor experiences for youth residents. During the school year Aaron is employed by the Truckee School District as an Instructional Assistant in the Special Education Department. He has been an active ski coach for over a decade and continues to serve as a Snow Ranger Coach at Sugar Bowl helping youth to grow through adventure and challenge. In addition to spending five amazing summers guiding for Gateway Mountain Center's school programs Aaron has been a Mentor with Gateway's Whole Hearts, Minds and Bodies program for three years. These opportunities allow him to continue to share his knowledge of the natural world, nurturing and inspiring the people he mentors.


Jenn Choi -Guide

Jenn Choi

Jenn is a recent transplant to the Truckee/Tahoe area, and was delightfully surprised to find herself working with youth in the outdoors with Gateway Mountain Center when she first arrived here in May of 2013. For a year, she taught high school English in Portland, Oregon, but soon found that the classroom was not her place; but teaching outdoors in the beauty of the Sierra has offered her and revealed to her a different approach and aspect to teaching in wholesome and refreshing ways. Other than working as a naturalist with Gateway, Jenn is a full time yoga instructor in the North Lake Tahoe area. Being outside and enjoying fully the gifts of nature is something that she values highly in her life—the unlimited amount of outdoor activities is what drew her to Tahoe in the first place. Rock climbing is her passion, however, you can find her cycling on the roads, mountain biking in the hills, snowboarding on the mountains, and backpacking in the back country as well!

Chris Kelly - Guide

Chris Kelly

In 2000, I started teaching with Naturalist at Large 5th -12th graders. Natural History and science were taught as well as fun group games and ropes courses/team building programs. I taught throughout California including: Joshua Tree, Catalina Island, Point Reyes, Malibu State Park and Sequia National Park. In 2001, I settled in Lake Tahoe where my outdoor adventures brought me to Squaw Valley as a board patroller and in summers I started guiding local trips with Tahoe Trips and Trails, working with Elderhostel and Corporate groups. I have worked with Gateway Mountain Center since 2007. During the school year I am now a Teacher's Aid in the 4th grade. I enjoy mtn. biking, skiing, snowboarding, and hiking.






Therapeutic Mentors



See Biographies above:

  • Rob Steffke
  • Peter Mayfield
  • Nancy Minges
  • Aaron Finley
  • Greg Bernstein



Rob Steffke - WHMB Mentor

Matt Sole

Rob Steffke has worked with at-risk teens for 15 years as a mentor, teacher, adventure guide, and counselor. His work has centered on creating community hubs that support young people in living from their gifts. Rob has been a teacher in alternative high schools and has created and implemented several activity-based mentoring programs. He founded and directed the San Luis Obispo Sober School, which serves high school and middle school students in recovery. He leads community discussions that support cultural transformation by re-imagining how we care for our youth. Rob has a Masters in Counseling Psychology from Meridian University, holds a Secondary Teaching Credential from Cal Poly San Luis Obispo, and is a Licensed Marriage and Family Therapist.



Jack Benter - WHMB Mentor

Jack BenterJack has dedicated his career to creating and leading youth and adult participants in life changing experiences. He graduated Magna Cum Laude with a BA in Education and began his career as a credentialed classroom teacher. Since then, he has held a variety a roles in the field of environmental and outdoor education, including program director, field instructor, wilderness guide, program coordinator, risk manager, and Yosemite Park Ranger Naturalist. He has also developed and implemented transformational programs and courses for individuals and renowned organizations, such as NOLS, Outward Bound, Naturalist At Large, and the Yosemite Institute. He continues to utilize the natural environment as the platform for growth and exploration in his personal life and in his life coaching practice. He has just completed a yearlong course with the Animas Valley Institute centered on leadership in a time of global change and is currently enrolled in a Masters in Counseling program at Meridian University.

Gamalier Gonzales -WHMB Mentor

Gamalier Gonzales

Gamalier A. Gonzales, began his career as a Personal Care Assistant assisting patients of all ages. Growing up with a younger brother with disabilities, he realized his calling to help those in need. After five years, Gami went back to school. After receiving his Associates of Occupational Studies of Medical Assisting, he worked for Northern Nevada Adult Mental Health Services for 2 years as a Mental Health Technician. He continued to work with the severely mentally ill in various institutions including high security facilities. Gami is currently enrolled in school perusing a BS in Nursing with a minor in Psychology and is currently working in a Wellness office caring for Medicare patients. Gami's unltimate goal is heal those in need; be that need physical or mental.


Marco Mora -WHMB Mentor

Marco Mora

Marco has worked with children of all ages ranging from kindergarten to highschool for 17 years. He began his career in 1998 as a tutor and mentor for inner city at-risk kids for the Los Angeles County Sheriff’s Youth Foundation. Marco holds a B.A. degree in Behavioral Science with a minor in Criminal Justice from Cal Poly Pomona. He earned his M.A. in School Counseling with a Pupil Personnel Services Credential from Loyola Marymount University. Currently Marco works for the Tahoe Truckee Unified School District as a School guidance counselor where he spends his time helping students with social, emotional and academic support. In addition to counseling, Marco is also the co-director for the Tahoe/Truckee Aim High program. When Marco is not busy fulfilling his many extensive professional roles, you can find him at the local plant nursery, as he is a Bonsai enthusiast. He also loves doing anything outdoors with his new puppy, Nickel and going on off-roading adventures.

Amye Cole -WHMB Mentor

Matt Sole

Amye has worked with youth and young adults in formal and informal education settings for fifteen years. She has worked in global political advocacy at the United Nations, served as Director of Admissions in private educational institutions, is an active member with the Truckee Rotary Club, and currently serves on a board of directors for three local non-profit groups. She is pursuing a M.A. in Counseling & Educational Psychology. She also holds an M.B.A. in Strategic Management. One of her favorite experiences with young adults has been leading a study abroad trip with seven college students to the remote Himalayas of northern Nepal, trekking over 200 miles and delivering medical supplies to pregnant women and young mothers. Amye’s passion resides in serving the community and forming sustainable partnerships to work collaboratively, though you’ll often find her mountain biking, backcountry skiing, road biking, listening to audio books, or just breathing deeply in the outdoors.


Daniela Di Piero -WHMB Mentor

Amye Cole

Daniella has taught in public schools, women’s prisons, juvenile detention centers, charter schools, grassroots community organizations, and nonprofits. She is the Founder and Executive Director of Movimiento, an organization that works with underserved teens and young adults in Oakland and Nevada County. She holds a Masters in Teaching from Brown University, a Masters in Counseling Psychology from Meridian University, and is a Marriage and Family Therapist Intern.


Emily Kistner -WHMB Mentor/Guide

Emily Kistner

Emily has worked with teens and adults in wilderness therapy settings for the past three years and believes in providing a positive outlet for the transformation of dissolution and separation into clarity and connection.  She is committed to the opportunity to be of service within her community and to sharing her experiences with others in a supportive and transformational way. Emily has over 18 years of experience in overcoming challenges and aligning the conscious and unconscious self. She has participated in cultural initiations and communication workshops as well as ancestral skill building and hand work. Emily holds a bachelors degree in Sociology and a double certificate of completion for the Interchange Counseling Institute.