Degree(s) HeldChris Bilbrey

B.A. Marketing, Fort Lewis College, 2002

Degree Sought

M.S. in Earth Sciences, Snow Science


Jordy Hendrikx,  Karl Birkeland, and Andy Gleason

Contact Information

Research Interests

Spatial variability of crack propagation in complex, wind-loaded terrain, using terrestrial Structure from Motion (SfM) to model snow distribution on wind-loaded slopes, and avalanche forecasting/ education.

Title of Research Project

The Effect of Slope-Scale Spatial Variability of Slab Characteristics on Propagation Saw Test.

Project Summary

Understanding propagation in complex, non-uniform terrain is critically important for avalanche forecasting and mitigation. Currently our understanding of how propagation varies at the slope-scale is limited, particularly on complex wind loaded slopes with a wide variation in slab properties. This study investigates the variability of slab properties (depth, SWE, hardness), and how that variability affects Propagation Saw Test (PST) cut lengths. We collected data from thirteen slope-scale transects on nine slopes in southwest Montana during the 2015-16 and 2016-17 winters. We utilized thin – blade penetrometer measurements (Borstad and McClung, 2011) during the second field season to index properties of the weak layer to hopefully help explain some of the variability we observed during the first field season. In addition, we utilized terrestrial based Structure from Motion (SfM) to build surface models of field sites with and without snow. Being able to quantify the temporal changes and spatial variability of snow depth may provide valuable information to better understand variations in snow distribution. Combined with additional statistical analyses, we hope this work will help us better understand the variability of crack propagation in complex, non-uniform terrain. 

Measuring Propagation Saw Test

Measuring Propagation Saw Test cut length (cm). Slab fracture was observed in this PST. Location: Middle Basin field site, Northern Madison Mountains, MT. (Photo: Chris Bilbrey)

Graduate Course Work

Graduate Snow Seminar (snow physics and avalanche dynamics), Statics, Physics, Chemistry, Statistics, Calculus, Geomorphology, Weather and Climate, Watershed Hydrology, GIS, Environmental Monitoring (automated environmental measuring equipment), and Remote Sensing.


Conference Proceedings/Presentations

Bilbrey, C., Hendrikx, J., Birkeland, K., and J.A. Gleason. The effect of slope-scale spatial variability of slab characteristics on propagation saw test, Proceedings International Snow Science Workshop, Breckenridge, CO 2016.


Bilbrey, C., Hendrikx, J., Birkeland, K., and J.A. Gleason. The effect of slope-scale spatial variability of slab characteristics on propagation saw test, Gallatin National Forest Avalanche Center Pro-Development Workshop, Bozeman, MT 2017.


Affiliations and Certifications

American Avalanche Association, Professional Member (2011)

Successfully Completed AIARE Level 3, Mt. Baker, WA (2016)

Level I and II Avalanche Certification, Silverton Avalanche School, Silverton, CO (2001 and 2008)

Avalanche Tech and Dog Handler, Colorado Rapid Avalanche Deployment Team, Flight for Life Air Medical Services, Durango, CO (2010 – 2013)

Type 1A Blasting Permit Holder, State of Colorado Division of Oil and Public Safety (2003 – 2013)

NREMT – Basic/ Intermediate (2001 – 2017)

CPR (2001 – Present)


Work Experience

Avalanche Center Internship (December 2016 – April 2017)

Gallatin National Forest Avalanche Center, Bozeman, MT


Graduate Teaching Assistant, Department of Earth Science (August 2015 – May 2017)

Montana State University, Bozeman, MT


Education Coordinator/ Avalanche Course Instructor (November 2013 – Present)

Friends of Gallatin National Forest Avalanche Center, Bozeman, MT


Professional Ski Patrol/ Lead Avalanche Tech (December 2002 – April 2013)

Wolf Creek Ski Area, Pagosa Springs, CO


Teaching Assistant, Snow Dynamics/ Geology 390 (January 2012 – May 2012)

Fort Lewis College, Durango, CO, Colorado State University System



American Avalanche Association Graduate Research Grant (2016)

Mazamas Research Grant (2016)

MSU – MAGIP GIS Scholarship (2016)

RedCastle Resources/ MAGIP Scholarship (2016)

Large grain facets and depth hoar crystals

Large grain Facets and Depth Hoar crystals (2mm grid). This grain type and weak layer is common to the snowpack in southwest Montana and during our field testing. (Photo: Chris Bilbrey)