Staff


Vickie Hormuth

Executive Director

A native of Colorado, Vickie is a lifelong skier who’s been recreating in the backcountry and over 20 years. Thanks to great mentors, she was an early adopter of avalanche and climbing education. Vickie’s passion for the outdoors led her to a career in the nonprofit realm spanning across a multitude of organizations over the past fifteen years including Outward Bound, the Colorado 14ers Initiative, Environmental Defense Center, The Nonprofit Support Center, and the American Alpine Club (AAC). While working in the nonprofit sector, Vickie has gained expertise in fundraising, strategic planning and program development, passion is for partnerships: working with companies, nonprofits and government agencies.

Vickie holds a B.A Geography with an emphasis in Hydrology from the University of Colorado, Boulder and serves on the Executive Committee for the State of Colorado Outdoor Recreation Industry Office. Vickie, her husband Scott and two step-sons split their time between Vail and Crested Butte, CO. When not skiing, she enjoys climbing, mountain biking and the occasional ultra-marathon trail race.


Liz Riggs Meder

Director of Recreation Programs

Liz Riggs Meder is the Director of Recreation Programs at AIARE and is based in Seattle. Liz is responsible for all aspects related to the development and delivery of AIARE’s Recreational Education programs, which includes curriculum development, managing the instructor training program, and overall program delivery and evaluation. Liz is an AIARE Instructor, occasionally works as a Cascade mountain guide, and holds an M.Ed from the University of Washington. A learning and cognitive science nerd, Liz loves combining her education interests with her love of traveling through the mountains.


Sean Zimmerman-Wall

Director of PRO Programs

Sean has joined the AIARE Staff as the Director of PRO Programs and bases out of Salt Lake City, Utah. He oversees the diverse team of Professional Course Instructors, collaborates with industry stakeholders and venue partners, and is responsible for the continued development of course curriculum. His experience as a Snowbird ski patroller since 2009 establishes his professional operational context and opens lines of communication across the industry. Working as a lead guide for Snowbird Backcountry Guides and as co-owner of Patagonia Ski Tours also gives him a connection to this segment of avalanche workers. In addition to teaching AIARE Recreational Courses, Sean serves as the Pro At-Large Trustee for the American Avalanche Association.


Brooke Retherford

Operations Manager

Brooke is the Operations Manager for AIARE after a long career in non profit operations and outdoor education in far reaches of the globe.  She is reasonable for the planning, execution, and review of AIARE’s PRO and Instructor Trainer courses. Brooke was lucky enough to be raised in the mountains of Colorado where her passion for adventure and wild places were nourished.  She holds a BA in Environmental Studies from the University of California, Santa Cruz and a MA in Conflict Resolution from the University of Denver. She now lives in Colorado with her life partner and two girls.


Jeff Hambelton

Motorized Program Manager

Jeff is responsible for oversight, development, and vision of AIARE’s motorized programs, including Professional, Instructor Trainer, and Recreational programs.  Jeff started snowmobiling in 2007, quickly adapting to a new mode of mountain access.   He completed his AIARE Instructor training in 2012 and joined the AIARE Pro Trainer staff in 2018. He was hired in 2013 by the Northwest Avalanche Center as a Professional Observer and remains on staff as the Snowmobile Education Coordinator.  He dedicates the majority of his winter to riding sleds with friends and teaching snowmobile based avalanche courses with a growing team of inspiring instructors.  Jeff resides near Mt. Baker where he enjoys a deep snowpack, loamy single-track, and the fall berry harvest.


Emma Walker

Curriculum Manager

Emma Walker brings 10 years of outdoor industry experience to her role as AIARE’s Curriculum Manager. She is responsible for managing recreational curriculum such as the fieldbook and online learning content, as well as AIARE’s education communications and support for instructor training and continuing education. Emma holds a master’s degree in outdoor and environmental education from Alaska Pacific University, where she completed her thesis research on decision-making dynamics among Denali guides. She has edited two volumes of The Snowy Torrents, a collection of avalanche accident data and analysis published by the American Avalanche Association, and her writing has appeared in Outside, Powder, and The Avalanche Review, along with her book, Dead Reckoning: Learning from Accidents in the Outdoors (Falcon, 2021). Emma lives in Boise, Idaho with her husband, trusty mutt, and a handful of backyard chickens.


Sarah MacGregor - PhotoSarah MacGregor

Member Services Manager

Sarah works as the backbone of day-to-day communications and office operations at AIARE, bringing in over a decade of experience in administration, management and IT and over 14 years of work in the outdoor industry as a guide and educator. As a Colorado native, she fell in love with snowboarding in high school and began splitboarding and rock climbing in her college years at Colorado State University where she studied Natural Resource Recreation and Tourism and Spanish. Sarah is currently an AIARE instructor and is trained by the American Mountain Guides Association (AMGA) in the Splitboard, Alpine and Rock disciplines. Her experience and training cohesively informs her ability to support the AIARE team and their diverse members. She is the first female AMGA trained splitboard guide in Colorado and actively makes it her goal to change that in her free time by elevating women in the mountains through teaching women’s specific programs and workshops. She is currently based in Gunnison, CO where you might find her around playing “hide and seek” with her dog Fawkes who is training to be a CRAD certified avalanche rescue dog for Monarch Mountain Ski Resort.


Azissa Singh

Women’s Mentorship Program Manager

Born and raised in South Carolina, Azissa’s early outdoor adventures included exploring backyard woods and streams. At the University of South Carolina, she began her journey as an outdoor instructor—a journey that has led her from field work instructing and guiding to managing outdoor programs for university, nonprofits, and commercial operations and everything in between. Azissa joins AIARE to do the work of creating more accessible and sustainable pathways to a career as an avalanche educator, with a focus on those who have traditionally been marginalized.