Date of Observation: 12/09/2022
Name: Zach Guy and Zach Kinler
Zone: Northwest Mountains
Route Description: Ruby Range from Lake Irwin to OBJ Basin
Observed avalanche activity: Yes
Avalanches: Natural persistent slab avalanches from D1.5 to D2.5 on NW to NE to SE aspects N/ATL. See photos.
Location: Lake Irwin (Robinson Basin, Owen, Ruby)
Location Specific:
Start Zone Elevation: ATL: Above Tree Line
Aspect: NE
Trigger: Natural
Trigger modifier:
Type: Hard Slab
Failure Plane: Old snow
Relative Size: R2 small
Destructive Size: D2 – could bury, injure, or kill a person
Avg. crown height (inches):
Avg. width (feet):
Avg. vertical run (feet):
# of people caught:
# of partial burials:
# of full burials:
Additional comments: Ruby x1, Owen x1
Location: Lake Irwin (Robinson Basin, Owen, Ruby)
Location Specific:
Start Zone Elevation: ATL: Above Tree Line
Aspect: E
Trigger: Natural
Trigger modifier:
Type: Unknown
Failure Plane:
Relative Size:
Destructive Size: D2 – could bury, injure, or kill a person
Avg. crown height (inches):
Avg. width (feet):
Avg. vertical run (feet):
# of people caught:
# of partial burials:
# of full burials:
Additional comments: Ruby/Owen saddle x 1, Owen East Fac x 2
Location: Lake Irwin (Robinson Basin, Owen, Ruby)
Location Specific:
Start Zone Elevation: ATL: Above Tree Line
Aspect: SE
Trigger:
Trigger modifier:
Type: Soft Slab
Failure Plane: Old snow
Relative Size: R1 very small
Destructive Size: D1.5
Avg. crown height (inches):
Avg. width (feet):
Avg. vertical run (feet):
# of people caught:
# of partial burials:
# of full burials:
Additional comments: Purple Peak
Location: Oh-Be-Joyful Basin
Location Specific:
Start Zone Elevation: NTL: Near Tree Line
Aspect: E
Trigger: Natural
Trigger modifier:
Type: Hard Slab
Failure Plane: Old snow
Relative Size: R2 small
Destructive Size: D2 – could bury, injure, or kill a person
Avg. crown height (inches):
Avg. width (feet):
Avg. vertical run (feet):
# of people caught:
# of partial burials:
# of full burials:
Additional comments: OBJ Peak
Location: Anthracite Creek (West side of Ruby Range, Marcellina)
Location Specific:
Start Zone Elevation: ATL: Above Tree Line
Aspect: NW
Trigger: Natural
Trigger modifier:
Type: Hard Slab
Failure Plane: Old snow
Relative Size: R2 small
Destructive Size: D2.5
Avg. crown height (inches):
Avg. width (feet):
Avg. vertical run (feet):
# of people caught:
# of partial burials:
# of full burials:
Additional comments: NW side of Richmond. Could have been D3
