As part of Vital Signs Monitoring, the North Coast and Cascades Network (NCCN) of the National Park Service (NPS) developed a protocol for monitoring landscape change using Landsat satellite imagery. The protocol was implemented at Mount Rainier (MORA) in 2013, North Cascades (NOCA) 2012, and Olympic National Parks (OLYM) in 2014 using LandTrendr (Landsat-based Detection of Trends in Disturbance and Recovery) algorithms developed by the Environmental Monitoring, Analysis, and Process Recognition Lab (eMapR) (formerly the Laboratory for Applications of Remote Sensing in Ecology (LARSE)) at Oregon State University.

Nine categories of landscape change in parks and surrounding areas from 1987 to 2017 were mapped and labeled. Eight categories were mapped at MORA and NOCA: Avalanches, Clearing, Development, Fire, Mass Movements, Progressive Defoliation, Riparian, and Tree Topplings. Winter Ice was added for OLYM only and it captures changes in vegetation damaged by heavy, long-lasting snow and ice followed by severe winds and generally characterized by broken tree branches. The Avalanche category captures long, linear change which partially or completely removes vegetation from the valley wall following a release of a large mass of snow down a mountain side. Clearings are areas under forest management where practices vary from thinning to clearcuts. The Development category captures changes associated with complete and persistent removal of vegetation and transformation to a built landscape. Changes due to Fire vary in intensity from full canopy removal to partial burns that leave behind a mixture of dead and singed trees. The Mass Movement category includes both landslides found on valley walls and debris flows associated with streams. Progressive Defoliation is a change type in which the forest cover remains but has declined due to insect infestation, disease or drought. Riparian changes are restricted to the valley floors alongside major streams and rivers and capture areas where either conifer or broadleaf vegetation previously existed and has been converted to river channel. Change due to Tree Toppling is evidenced by broken or topped trees, generally due to wind but sometimes to root rot. Only changes larger than 0.8 ha (2 ac) were mapped.

This version of the data set was generated by running LandTrendr in Google Earth Engine and is a replacement of the 1985-2009 data sets published in 2000; NPS Data Store Records 2282287 (MORA), 2282297 (NOCA), AND 2282298 (OLYM).