Montana Avalanche Map Layers

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"What's the danger?" Here are autogenerated DEM Shading rules for each advisory zone that allow for quickly adding avalanche danger, problems, and sun angle layers to CalTopo maps. Reports sourced from avalanche.org.

Show Instructions

Digital Elevation Model (DEM) shading let's you create custom shading schemes based on elevation, slope, aspect and tree cover.

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Avalanche Report

The selected elevation bands are not meant to be exact, but represent a characteristic of the terrain which varies locally.

The highest band, ATL (Above Tree Line), typically includes alpine areas beginning as the treeline transitions into open slopes extending to ridges and peaks.

The middle band, NTL (Near Tree Line), is typically a narrow transition zone between dense forests and treeless alpine areas.

The lowest band, BTL (Below Tree Line), typically extends from valley floors or snowline to near treeline.

Adjusting bands

The default elevation bands may not be accurate for the current zone, you can adjust the bands by dragging the sliders.

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Usage

You'll find that Terrain Modeling in the left pane will show layers that can be turned on and edited. The right pane will show Custom Layers that can be toggled on or off.

Select A Zone: Flathead Range & Glacier NP Swan Range Whitefish Range Bridger Range Cooke City Island Park Lionhead Area Northern Gallatin Range Northern Madison Range Southern Gallatin Range Southern Madison Range East Cabinet Mountains Purcell Mountains Bitterroot Rattlesnake Seeley Lake

Avalanche Report

Pre-populated CalTopo Map

2025-01-19 Avalanche Danger

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• Low danger (above 6101')
• Low danger (4401' to 6100')
• Low danger (below 4400')

2025-01-21 Wind Slab

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• All aspects (above 6101')
• All aspects (4401' to 6100')

Issued at: Monday, January 20, 2025 6:38AM
Issued by: FAC

Avalanche Report

Pre-populated CalTopo Map

2025-01-19 Avalanche Danger

Copy to clipboard

• Low danger (above 6101')
• Low danger (4401' to 6100')
• Low danger (below 4400')

2025-01-21 Wind Slab

Copy to clipboard

• All aspects (above 6101')
• All aspects (4401' to 6100')

Issued at: Monday, January 20, 2025 6:38AM
Issued by: FAC

Avalanche Report

Pre-populated CalTopo Map

2025-01-19 Avalanche Danger

Copy to clipboard

• Low danger (above 6101')
• Low danger (4401' to 6100')
• Low danger (below 4400')

2025-01-21 Wind Slab

Copy to clipboard

• All aspects (above 6101')
• All aspects (4401' to 6100')

Issued at: Monday, January 20, 2025 6:38AM
Issued by: FAC

Avalanche Report

Report not available. See GNFAC for more information.

Avalanche Report

Report not available. See GNFAC for more information.

Avalanche Report

Report not available. See GNFAC for more information.

Avalanche Report

Report not available. See GNFAC for more information.

Avalanche Report

Report not available. See GNFAC for more information.

Avalanche Report

Report not available. See GNFAC for more information.

Avalanche Report

Report not available. See GNFAC for more information.

Avalanche Report

Report not available. See GNFAC for more information.

Avalanche Report

Report not available. See IPAC for more information.

Avalanche Report

Report not available. See IPAC for more information.

Avalanche Report

Report not available. See WCMAC for more information.

Avalanche Report

Report not available. See WCMAC for more information.

Avalanche Report

Report not available. See WCMAC for more information.

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