CWMP 2016-2017 Winter Report
10
Summary of 2017 Trailing Data
Citizen scientists trailed animals 14 times over the course of the monitoring period,
and trailed five separate species (Table 2). Of these trailing events, three recorded
an animal crossing or entering the highway: a pair of coyotes crossed Eastbound I-
90 at Easton, a single coyote entering the Easton tree island (along the Easton
South transect) from Westbound I-90, and a coyote crossing from the Snoqualmie
Pass Underpass. Three trailing events followed elk at Denny Creek and Price
Noble. At both transects, elk were foraging along the highway, with no effort to
cross I-90 detected. Foraging and marking sign suggests elk are wintering along
the highway. Please refer to Appendix III for maps displaying the distribution of
trailing events across the five transects.
Table 2. The number of species trailed across the five transects. * denotes trailing events documenting an animal
crossing I-90.
Transect
Denny
Creek
Easton Gold Creek
Price
Noble
Snoqualmie
Pass
Species n trailing events N S N N S N S
Bobcat 4 1 1 1 1
Coyote 4 3* 1*
Elk 3 1 2
Marten 2 2
Mule Deer 1 1
American Marten Surveys
For the 2015-2016 Annual Winter Report, we reviewed all of the American marten
detection data collected over the duration of this project as well as the results of other
recent survey efforts for this species in the study area carried out by others. Based on this
review, we suggested that recent land use changes, specifically ski resort expansion at
Snoqualmie Pass, may have decreased the permeability of the landscape for American
marten. Additionally, while we documented the species just off of Interstate 90 north of the
roadway at our SnoPass transect, we have no documentation of the species close to the
roadway anywhere to the south, though we do have repeated observations from well off
the highway from the now terminated Hyak-Silver Fir transect. In total, our findings and
review further suggest that currently the Interstate and associated human development
adjacent to it may be acting as a complete separation for American marten populations
north and south of the road.
