Cascades to Olympics

Reconnecting the Cascades and Olympic Peninsula through wildlife crossings, habitat restoration, and collaborative conservation that keeps forests, rivers, and migration corridors connected for future generations.

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Our Approach

Reconnecting the Cascades and the Olympic Peninsula by restoring habitat, improving wildlife passage, and protecting the forest and river systems that link these landscapes.

The Olympic Peninsula is naturally isolated, and development pressures along I 5 and Highway 12 have made wildlife movement even more difficult. Our mission is to secure and restore the habitat corridors that species like wolves, elk, fishers, spotted owls, and marbled murrelets rely on. Through partnerships with Tribes, local communities, agencies, and landowners, we advance crossing structures, forest restoration, and long term protections that keep this landscape connected and resilient.

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Current Focus

Work We’re Doing to Achieve Cascades to Olympics Region Goals

Wildlife Crossings

We serve as a lead voice for terrestrial species conservation in the Chehalis Basin Strategy and the Aquatic Species Restoration Plan, ensuring that climate change and long term wildlife needs are fully considered in regional planning.

Our team uses modeling and wildlife monitoring to identify pinch points along Highway 12 and I 5, helping agencies prioritize locations where wildlife crossings, fencing, or habitat restoration will most effectively improve movement. We advocate for enhancements to existing underpasses and culverts including sites near the Toutle River, Prairie Creek, Skookumchuck, and the Newaukum River to strengthen current pathways for elk, deer, carnivores, and other species. We also promote flood damage reduction strategies that emphasize habitat restoration and land use improvements as alternatives to new dams.

Habitat Restoration

Across the Cascades to Olympics landscape, we work closely with landowners, Tribes, state agencies, and local communities to design and implement habitat restoration and corridor protection strategies.

Our role includes securing funding for forest habitat acquisition and restoration, with particular focus on the northern linkage where land protection opportunities are most urgent. By combining science based planning, community engagement, and targeted restoration, we help reconnect two of Washington’s most important mountain ranges. These efforts ensure that wildlife can move safely between the Cascades and the Olympics as climate, development, and infrastructure pressures continue to grow.

Impact & Results

A History in the Cascades to Olympics Region

For decades, the Cascades to Olympics region has been recognized as one of Washington’s most important wildlife connectivity landscapes. Through partnerships and science based planning, Conservation Northwest has helped reconnect habitats, improve wildlife movement, and advance ecological restoration across the region.

Long-term landscape vision (pre-I-5 focus)

Coalition and partner mobilization

Mainstreaming connectivity into basin-scale planning

Long-term landscape vision (pre-I-5 focus)

Conservation Northwest helped elevate the Cascades–Olympics linkage as one of Washington’s highest-priority wildlife connectivity gaps well before major state investment, positioning the corridor alongside the better-known Cascades-to-Canada work.

Coalition and partner mobilization

The program has played a key convening role with Tribes, transportation agencies, and regional collaboratives (including the Cascades to Coast effort) to build the political and technical support needed for large-scale crossing and habitat investments.

Mainstreaming connectivity into basin-scale planning

Through sustained engagement in the Chehalis Basin process, CNW helped embed wildlife connectivity and habitat function into what was historically a flood-control-dominated conversation — broadening the policy lens beyond single-purpose infrastructure.

Impact & Results

Our Key Accomplishments for Cascades to Olympics

From protecting critical landscapes to advancing collaborative forest restoration, these efforts deliver lasting benefits for wildlife, habitat connectivity, and climate resilience.

I-5 Wildlife Crossings

Science-Based Connectivity Planning

In 2024, the program helped complete the I-5 wildlife crossing feasibility study, delivering the first science-based assessment of priority locations needed to reconnect the Cascades and the Olympic Peninsula.

Securing Key Wildlife Linkages

Land Protection for Connectivity

Since the early 2020s, the program has supported land acquisitions for Tribes and conservation partners in key linkage zones crossing I-5, protecting habitat essential for long-term wildlife movement.

Chehalis Basin Restoration Planning

Science-Driven Flood and Habitat Solutions

The program contributed to development of the Local Actions Non-Dam Alternative for the Chehalis Basin Strategy, advancing a science-driven approach to flood mitigation and habitat restoration without new dam construction.