For more details about
the tool, or interest in
production of an LHA,
please contact:

George Wilhere,
Senior Research Scientist
Habitat Program
(360) 902-2369
(360) 902-2946 FAX

For more information on habitat issues, please contact the
WDFW Habitat Program.
Phone: 360-902-2534

For more information on WDFW managed lands including wildlife areas, please contact the
WDFW Wildlife Program.
Phone: 360-902-2515


South Lewis County Subarea

To develop a clearer picture of the quality and sustainability of habitats in South Lewis County, with a focus on a portion of the watershed defined by the county as a planning subarea, WDFW characterized the landscape based on the needs of several focal species.  Appendix C of the South Lewis County Habitat Assessment Report describes the focal species selection process in more detail.  Collectively, the chosen species:

  • are closely associated with the varied habitat types found in the south county area;
  • are sensitive to patch size, alignment of complementary habitat, or connectivity features;
  • include representative birds, mammals, amphibians, and reptiles;
  • include herbivores, insectivores, and carnivores.

The following examples illustrate the Subarea LHA techniques.  Assessment results were combined to delineate a portion of the planning subarea particularly well-suited for providing wildlife habitat into the future, and to distinguish areas relatively amenable for development.  These studies were all applied to the entire watershed area to allow a qualitative assessment of habitat connectivity.

Hermit WarblerForest Interior Birds – Hermit Warbler

Hermit Warblers are small, forest interior specialists.  These birds require large contiguous expanses of forest (~500 acres) which allow them to avoid the edge of the habitat patch.  Primary association of Hermit Warblers is with mature and old growth conifer forest; secondary association is with mature and old growth hardwood forest, or mixed conifer/hardwood forest. 


Forest Interior Bird Habitat

Hermit Warbler Analysis Map
VIEW: Hermit Warbler Analysis Map

Green indicates forested habitat patches greater than 500 acres.  These are large enough to support highly sensitive forest interior specialists, like Hermit Warblers.  The South Lewis County Subarea is defined by the rectangular outline.  The full analysis area includes all sub-watersheds affecting the flow of water within the subarea.

Short-eared OwlOpen/Grassland Birds – Short-eared Owl

Short-eared Owls are mid-sized owls, primarily winter residents in South Lewis County.  Important hunting habitats for Short-eared Owls are open/grasslands, juxtaposed with shrub habitats, wet meadows, herbaceous wetlands, and open water.  Territory size can exceed 200 acres.


Short-eared Owl Habitat

Short-eared Owl Analysis Map
VIEW: Short-eared Owl Analysis Map

This map shows the distribution of habitat patches consisting of open/grassland areas and wetlands, which exceed 200 acres.  As with the previous map, yellow areas indicate ownership, and are unrelated to the habitat analysis.  The red outline is associated with planning for Mt. St. Helens events and is also unrelated to the habitat analysis.

Northern Red-legged FrogStill Water Associated Amphibians – Northern Red-legged Frog

Northern Red-legged Frogs are amphibians that breed in still water habitats, such as ponds and wetlands.  These amphibians undertake regular seasonal movements away from breeding areas and into upland habitats during the course of the year.  Distances moved are typically 1-5 miles, which is significant, given the small size of these animals.


Reptiles and Amphibians Cost Distance Analysis

Amphibian Connectivity Analysis Map
VIEW: Amphibian Connectivity Analysis Map

The analysis map models habitat permeability for this species in the south county area.  Any shade of green shows where complexes of wetlands are relatively well connected by appropriate upland habitat.  Because of the size and travel speed of Northern Red-legged Frogs, roads can be significant barriers to this natural movement.  Even relatively low traffic intensity can lead to high direct mortality for these animals.  In the absence of special crossing structures, roads colored red are considered complete barriers to movement.

Synthesizing Results – Habitat Focus Area Delineation

The South Lewis County Subarea planning process was undertaken to define how economic and residential growth will proceed into the future.  WDFW analyses provided information that local citizens and decision makers could use to locate development in areas where land use changes would be less impacting to wildlife.  WDFW LHA studies at the county, watershed, and subarea scales increased the understanding of current general habitat conditions within and surrounding the planning area.  Additional LHA analyses looked more closely at habitat potential for a group of representative species.  The final step of the LHA process was to use all of the analyses to delineate the portion of the subarea best suited for managing with an emphasis on habitat.  Ideally, this area would be located within the planning subarea and could provide for designated open space under the Growth Management Act.  In addition, it would include all important habitat types and features, and would support a relatively high level of connectivity.

Conservation Focus Area

Proposed Habitat Focus Area
VIEW: Proposed Habitat Focus Area

Shown within the dashed lines in the accompanying map, the area encompasses the Lacamas Creek corridor as well as some adjacent habitats.  Lacamas Creek is one of three salmon-bearing creeks in the south county area.  In the individual focal species analyses, this area appeared repeatedly as a zone that currently provides forested, open, and wetland habitats.  It also contains areas of remnant oak and prairie.  The focus area currently features a relatively high degree of connectivity, interrupted primarily by the major roads that cross the corridor.

Successful conservation within this focus area would not require a complete lack of development or economic activity.  The recommended goal would be to limit fragmentation of existing habitats within the zone and to enhance connectivity, when possible.  Farmlands are currently serving as part of the effective habitat mosaic in the area; protecting these working lands from conversion to residential, commercial, or industrial uses can also support conservation.