There are two components of this Sample Design: 1) abundance assessment, 2) spatial distribution (extent)

Within the stream being assessed, the habitat has been delineated into approximately 1 km reaches (stratum). Within each reach there are approximately 10-100m Sampling Units (sites). All reaches will be selected for the assessment, with a random (drawn) selection of 1-2 100m sites per reach.  Abundance assessments of the Westslope Cutthroat Trout population will be conducted within each selected project site. Prior to conducting the assessments, each site will be evaluated in the field to ensure it contains representative habitat; if not, an alternative randomly sampled site will be chosen If no fish are observed in a selected site, a secondary site within the reach will be assessed.

For the secondary component, single-pass electrofishing will be conducted in a non-random fashion within each reach to determine the spatial extent of the population; this is a simple presence/absence survey to define total extent (i.e., upstream, downstream).

The assessments will be conducted in a single event (one time) over the course of a two-week period (August-September timeframe) to ensure equal distribution of the population and limited movement.

Reach 1 is the lowest reach above the passage barrier at the road (culvert), where the non-native fish (i.e., Brook Trout) were mechanically removed, allowing native Westslope Cutthroat Trout to naturally reoccupy the remaining habitat. Within Reach 1, a minimum of one site will be assessed, but may be increased to two sites. Reach 2 is a mix of potions within the non-native fish management section and natural distribution of allopatric Westslope Cutthroat Trout. Assessments will be conducted in two sites within reach two: one within the managed section and one within the natural distibution section.