Shoreline, WA Tree Protection: Heritage & Protected Trees (2026)

The Development Code's definitions chapter, SMC § 20.20.048, defines 'Tree, Landmark' as any healthy tree over 24 inches in diameter at breast height that is worthy of long-term protection because of a unique combination of size, shape, age, location, or aesthetic quality for its species, or because it carries cultural, historic, or ecological importance, or is a regional erratic. That definition points to the operative protection at SMC § 20.50.350(F), Landmark Trees, within Chapter 20.50's tree conservation, land clearing, and site grading standards. Under that subsection, a tree the city has actually designated as a landmark tree, defined there as 30 inches or larger in diameter, or particularly impressive due to species, size, shape, age, historical significance, or an outstanding row or group, may not be removed unless the applicant meets the exception requirements of subsection B of the same section.

The Director is charged with establishing the criteria and procedures for designating landmark trees, and designated trees can be marked in the field: the same subchapter elsewhere authorizes plaques, signs, or markers for landmark tree designation with city-approved placement and design. Landmark trees sit above 'significant trees,' defined at six inches dbh and protected under the same subchapter's retention percentages, and above 'hazardous trees,' which may be removed regardless of designation. Removing a designated landmark tree without meeting the subsection B exceptions is enforced as a Chapter 20.50 code violation and public nuisance, subject to the notice-and-order and civil penalty provisions of SMC §§ 20.30.740 and 20.30.770, including added penalties under § 20.30.770(D)(2) for unlawfully removed trees.