Explore our world-class mountaineering library, apply for one of our grants, and dig in to your member resources.
Mathew Brock, Director of Special Collections & Media (He/Him)
Mathew Brock
Mathew Brock joined the Mazama staff in February of 2015. He holds a Master of Library and Information Science from the University of Washington and a Bachelors of Social Science from the University of Alaska Southeast. Besides overseeing the Mazama Library and Historical Collections, Mathew also is managing editor for the Mazama Bulletin and oversees a variety of areas in the day-to-day operation of the Mazamas.
Mathew first climbed South Sister as a teenager. Later, while living in Alaska, he developed a love of hiking, backpacking, rock climbing. He completed BCEP in the Spring of 2016. Besides being outdoors, Mathew enjoys traveling, cooking, building things, and spending time with his wife and daughter.
Brendan Scanlan, IT & Operations Manager (He/Him)
Brendan Scanlan
Brendan Scanlan joined our staff in March of 2021 and serves as the IT & Operations Manager. Brendan brings a diverse background of database, program, and project management to the Mazamas. Prior to joining the Mazamas, Brendan worked in management consulting with a focus on non-labor cost reduction, IT systems implementation, and network development. Brendan also served on multiple non-profit boards in Chicago before moving to Portland.
Outside of work, you can find Brendan playing with his dog Winston, rock climbing at Smith Rock or one of the local crags, backpacking in the wilderness, baking bread or making pasta, or snowboarding down a steep slope.
Chelsea Tossing, Executive Director
Chelsea Tossing
Chelsea Tossing joined the Mazamas as Executive Director in January 2026, bringing nearly six years of nonprofit leadership experience from Cottonwood Institute, a Colorado-based organization connecting young people with nature through environmental education and outdoor adventure. As Associate Director, she co-led strategic planning, managed a team of 20 staff and instructors, and developed programs that created career pathways for students into outdoor professions. Her background includes public school teaching and curriculum design for interdisciplinary outdoor education programs.
An avid climber, bike packer, and trail runner, Chelsea spent ten years exploring the sandstone canyons and high peaks of Colorado before relocating to the Pacific Northwest. She is passionate about building communities and expanding access to wild places, and looks forward to learning and growing alongside Mazama members, volunteers, and staff.
