NORTH YUKON PLANNING REGION:
LMU 4: Northern Richardson Mountains and Foothills
Sub-unit #4B: LaChute River
Land Use Designation
Integrated Land Management Area, Zone II
Land Status
Yukon public land and VGFN S-Site (S-16A)
Traditional Territories
Vuntut Gwitchin First Nation and Tetlit Gwich'in Council (Secondary Use Area)
Area
1,287 km2 (2.1% of Region)
![NY_LMU4B_map](https://planyukon.ca/wp-content/uploads/NY_LMU4B_map.jpg)
Biophysical Setting (LMU 4)
Setting
Remote mountainous unit with sub-arctic conditions.
Ecoregions
British Richardson Mountains.
Bioclimatic Zones
Taiga Shrub, Alpine and Tundra (minor).
Habitat Types
High elevation sparsely vegetated, herb, shrub and rock; low elevation coniferous forest and shrub; minor wetland and riparian.
Watersheds
Porcupine River (Bell, Little Bell and Waters rivers, headwaters of Driftwood River).
Image Explanation
Bell River corridor in Northern Richardson Mountains is a significant Porcupine Caribou and moose habitat. (CWS photo)
![NY_LMU4B_aerial](https://planyukon.ca/wp-content/uploads/NY_LMU4B_aerial.jpg)
Cumulative Effects Thresholds
Relative to LMU Size*
Surface Disturbance (%)
Linear Disturbance (km/km2)
Current disturbance (2020)
0.019
0.030
Cautionary
0.150
0.150
Critical
0.200
0.200
On the ground amounts**
Surface Disturbance (km2)
Linear Disturbance (km)
Current disturbance (2020)
0.24
38.4
Room under cautionary threshold***
1.69
154.6
Cautionary
1.93
193.1
Critical
2.57
257.4
*These are proportional to the size of the LMU, and correspond to table 3-2 of the Approved Plan. They are measured in the % of the LMU that can be disturbed (“Surface Disturbance”) and in km/km2 (“Linear Disturbance Density”).
**These are amounts that can be measured and apply to the whole LMU and would be more familiar to project proponents and regulators. They are measured in km2 of disturbance and in km of linear disturbance (e.g., roads, trails and cutlines).
***How much more disturbance can be added to existing disturbance before the cautionary threshold is reached.
Cumulative Effects Indicators
Surface Disturbance
Linear Disturbance
Cautionary
Critical
Ecological Resources
Porcupine Caribou
Caribou concentrated use area. Porcupine herd may be present in at least three seasons, including fall migration, rutting, and winter.
Moose
Significant seasonal habitats along LaChute River corridor.
Marten
Low - moderate winter habitat.
Sheep
Status uncertain; significant sheep habitats identified in adjacent LMU #4C.
Fish
Potential over-wintering habitat in LaChute River.
Other Species
Significant grizzly Bear habitat in lower LaChute River valley.
Wetlands and Lakes
Very few; lower LaChute River in vicinity of Lapierre House most significant.
Riparian Areas
LaChute River and few large tributary streams to Eagle River.
Major River Corridors
None
Heritage, Social and Cultural Resources
VGFN Heritage Routes and Sites
Old Crow to Ft. McPherson trail, via Salmon Cache and Lapierre House. Traditional use and culturally significant area for Gwich’in First Nations.
Other Heritage and Historic Resources
Many documented archaeological sites.
Current Community Use Areas
Limited use; most activities occur in adjacent Bell and Rock River corridors (LMUs #4C and #8B).
Economic Development
Transportation and Access
No existing transportation infrastructure. A conceptual access route has been identified in this unit*.
Traditional Economy
Winter travel on Old Crow – Ft. McPherson Trail; subsistence harvesting.
Tourism and Recreation
High values in southern portion of unit, adjacent to Dempster Highway. Low levels of activity.
Oil and Gas Resources
Low - moderate potential; northern margin of the Eagle Plain oil and gas basin.
Mineral Resources
Very low potential.
Aggregate (Gravel) Resources
No identified resources; river gravels or crushed rock offer potential sources.
Forest Resources
* Source: Yukon Government, Department of Energy Mines and Resources. 2003.
Special Management Considerations
- Important Porcupine Caribou Herd concentrated use area.
- High heritage values with many documented archaeological sites.
- Old Crow – Ft. McPherson winter trail.
- Tetlit Gwich’in Secondary Use Area.
- Potential Yukon North Slope transportation corridor options may require consideration.
These gauges show how much of each disturbance indicator there is in the LMU with the needle and the large number near the middle. The colours indicate disturbance level zones or thresholds. If the needle is in the white zone, no threshold has been reached.
The Dawson Planning Commission gives a details of their similar (but slightly different) Cumulative Effects Framework on their website.
![PW_NY_gauge](https://planyukon.ca/wp-content/uploads/PW_NY_gauge.png)
Cautionary
Critical