The Pacific Northwest Region of the Lewis & Clark Trail Alliance is a membership organization dedicated to advancing public knowledge and awareness of the historic, social, and cultural significance of the Lewis and Clark Expedition. Established in 2021, the regional group brings together people of varied ages and interests who enjoy exploring the expedition’s history and its lasting connections to the Pacific Northwest.

Its activities include supporting the preservation of expedition-related sites and organizing educational projects, programs, and field trips. Members gather throughout the region for talks, service projects, hikes, and visits to places associated with the explorers. They also share knowledge through classroom presentations, historical research, writing, and hands-on demonstrations. The organization connects communities in Idaho, Oregon, and Washington through local chapters and events.

The Alliance provides resources such as maps, publications, newsletters, and event listings. Membership is managed through the national Alliance, where visitors can sign up or renew online.