Modoc Contextual Region

The “contextual region” is bigger than the planning region, and is defined in such a way as to include likely core area destinations/sources outside of the planning area, within a reasonable distance (<50 km maximum).

To define this boundary to buffer the Modoc Planning Region, we buffered the Modoc Plateau by 2 km, then selected all of the sub watersheds this intersected. We did the same for the Northwest Basin And Range Ecoregion Subsection in California but by 10 km since the watersheds are smaller in the mountains and key core areas were missed by the 2 km threshold. (As a quick proxy for core areas we used large areas with over 0.75 value of Terrestrial Intactness.)

For Nevada, we called Mark Freese of Nevada Department of Wildlife for advice. Hence, we made sure to not leave any space between our contextual region and the Northwest Basin and Range Synthesis. Then we made sure to include the two important mule deer seasonal migration corridors near the boundary.Finally Mark recommended we include all of the Eagle Lake and Surprise Valley BLM Field Office boundaries, which also include California. We were not sure about using the Surprise Valley boundary, but doing so also allows the inclusion of a key pronghorn antelope core area in the eastern corner of the region (Sheldon NWR). We made a union of these factors, and then selected all of the sub-watersheds that this union intersected.

In Oregon, we hand selected the watersheds between the California or Nevada Border and the first major highway to the North.

Finally, we noticed that a key core area destination and/or source near Crater Mountain that likely connects to one near Bald Mountain was not included.So we hand selected the approx.15 X 15 km suite of subwatersheds there and added this to the region.