This species is known from moist coniferous forests and open areas. It is often found on wet substrates near seepages, streams, lakes, and rivers, in addition to talus slopes (especially well-shaded, north-facing slopes). It is a semi-aquatic to terrestrial species, and while it does not require standing or flowing water at any stage of its life cycle, individuals are most often observed in very moist conditions (McIntyre 2003, Olson and Crisafulli 2014). It can also be found under bark, in and under logs, and in leaf-litter in wet weather. Individuals within the Coastal subpopulations tend to make use of downed wood for cover (Jones 1989, Jones and Atkinson 1989, Wilson et al. 1995, Blessing et al. 1999), while those in the Cascade Range subpopulations are more often found in cracks and fissures of saturated rock faces and in or under rocky accumulations from colluvial deposition (McIntyre 2003, Olson and Crisafulli 2014). This species has also been recorded within caves, where they occur under surface debris in seep-like or moist portions of the cave, such as near the entrance (Aubry et al. 1987, Olson and Crisafulli 2014). In a study of small order streams, McIntyre (2003) reported that this species is likely associated with a <5% canopy cover on stream valley walls, and with stream substrates dominated by boulders, bedrock, and soils. McIntyre (2006) found that the probability of occurrence increased with increasing proportions of seep face having both dry and sheeting hydrology. These findings suggest that this species may be sensitive to desiccation, and that hydrology and substrate are of the greatest importance in its habitat, followed by vegetation (McIntyre 2003, 2006, Olson and Crisafulli 2014). In a study conducted by Raphael et al. (2002), this species was only found in old growth forest, with lower densities observed in old growth forest buffers that were 10-30 m in width. No individuals were observed in sites that had been clearcut and regrown, with the mature stand ages spanning 35-100 years, or in any other sites that had undergone more severe harvesting. This suggests that this is an old growth forest associated species, and that it is highly sensitive to habitat disturbances that are associated with clearcutting along streams (Raphael et al. 2002, Olson and Crisafulli 2014). This suggests that this is an old growth forest associated species, and that it is highly sensitive to habitat disturbances that are associated with clearcutting along streams (Raphael et al. 2002, Olson and Crisafulli 2014). However, this species was able to persist in areas that were decimated during the Mt. St. Helens eruption of 1980. This persistence led McIntyre (2003) to conclude that the species may be reliant on microhabitat conditions, and that where these conditions exist the species can occur. These conditions may be more pervasive in old growth forests, but can be found in other localities as well.

At least nine clutches have been found in nature, with seven found in the Olympic Peninsula and two in the Willapa Hills (Olson and Crisafulli 2014, Hayes et al. 2018). Of the eight sites where some landscape description exits, four clutches were found in contiguous old-growth forest, one in an old growth buffer along a stream where the uplands had been harvested, and three were found in second-growth landscapes (Hayes et al. 2018). The eggs develop directly without a free-living larval stage. While the exact breeding season is unknown, it is likely that courtship occurs in the spring and/or fall and that oviposition occurs in the spring (Nussbaum et al. 1983, Olson and Crisafulli 2014). Females likely breed every two years, and it is possible that longevity may be around 12 years (Jones and Crisafulli 2005, Olson and Crisafulli 2014).

This species is endemic to Washington state in the USA, where it occurs in three discrete geographic areas: the Willapa Hills, the Olympic Peninsula, and the Washington Cascade Range. The subpopulations in the Willapa Hills and Olympic Peninsula are separated from each other by the Chehalis and Willapa Rivers. The Puget Trough then forms a physical barrier between these two more coastal subpopulations and that of the Cascade Range (Olson and Crisafulli 2014). These barriers likely limit the regional distribution of this species. It coexists with the Dunn’s salamander (Plethodon dunni) where their ranges overlap, southeast of South Bend, Pacific County, Washington (Stebbins 1985). This species generally occurs in small isolated subpopulations. It can be found at elevations ranging from 4–1,655 m asl (Olson and Crisafulli 2014). The extent of occurrence (EOO) of the mapped range is 44,438 km². The full range extent may not be known. This uncertainty is highlighted by the considerable range extension of a close relative of this species, the Coeur d’Alene Salamander (P. idahoensis), following additional survey effort (Olson and Crisafulli 2014).

Conservation Actions In-Place
This species is adequately protected in Mount St. Helens National Monument and Olympic National Park. Across its range, a majority of known sites occur on protected lands. It is listed as a Sensitive Species by the USDA Forest Service and Bureau of Land Management (BLM), and is a Washington State Candidate Species. In the Cascades Range portion of its range, this species is managed under the federal Survey and Manage Standards and Guidelines on Forest Service lands (Olson and Crisafulli 2014).

Research Needed
More information is needed on this species' distribution, population status, ecology, and threats. Specific information gaps include the distribution of the species, its colonization capacity, threats to the species, and the efficacy of alternative riparian buffer widths and other mitigations in maintaining populations and habitat conditions (Olson and Crisafulli 2014).