Instructor Bios & Contact

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Despite the volunteer status of the two lead instructors (since they earn their livings off the snow), they bring many professional credentials to their teaching, as well as many years of ski touring experience. And in addition to their NSP instruction in avalanche safety and mountain travel/rescue courses, both have undergone additional avalanche instructor training from the American Institute for Avalanche Research and Education (“AIARE”), and both are members of the American Avalanche Association.

Instructor of Record

Jonathan Shefftz patrols for Northfield Mountain and the Thunderbolt Ski Patrol. He is a PSIA-certified ski instructor for both alpine and nordic, U.S. Ski Association alpine race coach, organizer of a ski mountaineering race series (with personal wins at seven different venues), member of the Governing Board of the American Avalanche Association, recipient of the NSP Eastern Division Outstanding Nordic Patroller of the Year award (as well as runner-up at the national level), and organizer (as well as past presenter) for the Eastern Snow and Avalanche Workshop. His avalanche training includes Level 1 from the National Ski Patrol and both Level 2 and 3 from Chauvin Guides International. In addition to the Northeast, his ski touring and ski mountaineering has mainly been in the Sierra and especially the Pacific Northwest (having skied from the summits of eleven volcanic peaks above 10,000 feet, including Rainier as the highest and Glacier Peak as the least accessible). He has published extensively on the assessment (both quantitative and qualitative) of avalanche incidents and also written comprehensive reviews of avalanche beacons and other ski gear.


Mark Renson is a National Ski Patrol Alpine Senior Patroller and member of the Mad River Glen and Mount Washington ski patrols. His U.S. avalanche training includes Level 1 from Jackson Hole Mountain Guides, Level 2 from Chauvin Guides International, Level 3 from the American Avalanche Institute, and the National Avalanche School. He also has a Canadian Avalanche Skills Training (“AST”) Level 2 Certificate via the Ski Mountaineering Leadership Course from SME. In addition to the Northeast, his ski touring and ski mountaineering has mainly been in British Columbia and the Canadian Rockies.