This document presents two classifications for Glacier Bay National Park and Preserve: landcover classes and plant associations. These classifications provide resource managers with essential information to understand the vegetation and ecology of Glacier Bay National Park and Preserve. This document also provides a review of Glacier Bay's ecological literature, climate, vegetation, landscapes, major processes, and the project's methods. The classifications were developed by the National Park Service Landcover Mapping Program, Inventory and Monitoring Program, Alaska Regional Office (AKRO) in cooperation with the Alaska Natural Heritage Program (AKNHP). AKNHP also developed, in cooperation with AKRO and the National Wetlands Inventory (NWI), the digital landcover map to which the landcover classes and plant associations are linked.