The Pacific Northwest Chapter of the International Society of Arboriculture (PNW-ISA) is a member organization for arborists and urban foresters. We bring together professionals from Alaska, Idaho, Oregon, Washington, and British Columbia. Since 1979, we have been a resource and advocate for the green industry.

Our mission is to foster a greater appreciation of trees and promote the professional practice of arboriculture through education, research, and technology.

We pride ourselves on being the premier source for information about proper tree care in the Pacific Northwest. Reaching out to both professionals and the general public, we dispel myths about tree care and encourage best practices in the field. ISA Certification Programs are the gold standard for working arborists. Through our work on certification and continuing education, we foster professional growth and connect green industry businesses with qualified tree experts.

PNW-ISA is registered in the State of Oregon as a 501(c)(3) nonprofit organization. Any charitable donations you make to us are tax-deductible to the full extent of the law. Our federal employment identification number (FEIN) is 91-1492542.

We strive to:

  • Meet member needs with a balance of programs and products

  • Advocate for professional tree care as an important component of healthy communities

  • Encourage quality tree care among our members and the general public

  • Recognize varying levels of expertise within the industry and develop appropriate programs to meet that diversity

  • Advocate for advances in arboriculture and urban forestry throughout the Pacific Northwest

  • Support arboricultural research and the distribution of research findings

  • Run a healthy organization with exceptional standards for participation, leadership, and accountability