In the 30 years since its creation, has Portland, Oregon's, urban growth boundary (UGB) become something more than a regulation? Spirited debate about its impacts on land uses and values has inspired vivid descriptions by both supporters and critics and spurred the imagination of artists and creative writers. Purpose: The UGB has become a symbol, metaphor, and touchstone, as people read complex meanings into it that go beyond its simple legal function. This article looks at the UGB as a cultural icon. It explores the increasingly complex ways in which people have tried to describe, understand, and interpret the UGB as part of the regional landscape as well as the regulatory system. It examines metaphorical descriptions of the UGB as well as the growing body of depictions in nature writing, poetry, novels, photography, performance art, songs, and other exercises of the artistic imagination. Methods: We review how supporters and critics of the UGB have described it and how artists have depicted it in various media. Results and conclusions: Although many planning projects have become icons, few planning regulations have done so. Artistic interpretations have familiarized and humanized the UGB and embedded it in the consciousness of everyday life. Artists thus make the invisible more visible or legible. Acting as a viewfinder, the UGB offers an opportunity for conversation and interpretation from multiple perspectives. Takeaway for practice: In the world of 21st-century planning theory there is a strong assumption that many voices engaged in overlapping conversations can help shape more equitable and sustainable cities. Creative depictions of Portland's UGB show the role of cultural actors in shaping and enriching such conversations.