Most protected areas, including Steigerwald Lake NWR, need to be connected to other protected areas for their ecological functioning, including for having viable wildlife populations. Changes in land use (e.g., forestry practices, agriculture, urbanization), water management (levees, dams), environmental changes (e.g., increased fire frequency and intensity, and changes in precipitation and associated peaks and lows in river flows) can all affect the ecological connectivity of Steigerwald Lake NWR to its surrounding aquatic, semi-aquatic, and terrestrial habitat types. Other protected areas near Steigerwald Lake NWR along the Columbia River include Ridgefield NWR, Franz Lake NWR, and Pierce NWR, and connectivity along the Columbia River to these other protected areas is especially important for aquatic and semi-aquatic species.

Ecological connectivity to higher areas further away from the Columbia River is a concern at all four NWRs. WA Highway 14 is the busiest road between Steigerwald Lake NWR, Franz Lake NWR and Pierce NWR and the higher areas further north. In addition, Evergreen Way and a railroad parallel WA Highway 14 at Steigerwald Lake. I-5 parallels the Columbia River further to the west and is the busiest highway between Ridgefield NWR and Lewis River and its tributaries as well as higher areas to the east.

Large mammals (e.g., Columbia white-tailed deer, mule deer (black-tailed deer), elk, and black bear that cross highways at-grade are also a human safety issue. Other concerns include connectivity and direct road mortality for smaller mammal species (e.g., beaver (Castor canadensis)), and amphibians (e.g. western toad (Anaxyrus boreas). Finally, non-motorized access to the trails of Steigerwald Lake NWR from the urban area north of WA Highway 14, and north of Evergreen Way and the railroad, is a safety concern.

The goal of this project is to explore potential measures aimed at reducing collisions with large wild ungulate species (most notably mule deer (black-tailed deer) and elk), along WA Highway 14, Evergreen Way, and I-5, and improve connectivity for large wild mammals (e.g., Columbia white-tailed deer, mule deer (black-tailed deer), elk, bobcat, mountain lion, coyote, and black bear), and small species (e.g., amphibian and reptile species) between the four Refuges and the higher areas further away from the Columbia River. In addition, we explore non-motorized access to Steigerwald NWR from the built-up area of Washougal and a nearby school.