In 1986, the first guidebook to tree diseases in the Great Plains was published by the U.S. Forest Service Rocky Mountain Research Station. Master gardeners, arborists, plant pathologists, pest management specialists, farmers, foresters, and other land managers used this guidebook for over 30 years to successfully diagnose and treat tree diseases across Kansas, Oklahoma, Nebraska, North Dakota, South Dakota and other Great Plains states. Trees in this region are highly valued for their shade in cities, as windbreaks on farms, for use in agroforestry systems, for providing wildlife habitat, and more. In 2016, an updated version of Diseases of Trees in the Great Plains, was released. The book identifies tree hosts, tree distribution, disease symptoms and signs, disease cycles, and management strategies for 84 hardwood and 32 conifer diseases found in the Great Plains. The book also includes color illustrations, a glossary of technical terms, and indexes of hosts and pathogens. The book covers diseases of foliage, roots, stems, and branches soil-borne and wilt diseases, and the safe handling and use of pesticides. The book's chapters are grouped into hardwood and conifer diseases, then classified by the part of the plant being affected, each following a standard format. Twenty-seven authors contributed to the publication, providing the most comprehensive set of information available on tree diseases in this region of the country. The book was made possible because of the unique relationship between the state foresters, the U.S. Forest Service, and the Great Plains Tree Pest Council. This collaborative group leveraged resources to produce this book in response to stakeholder requests. This resource is critical where environmental factors not only create unique conditions for trees, but also for a unique set of forest disease complexes. These environmental factors are projected to become more erratic and extreme under future climate; increasing the need for strategies that will lead to better adapted tree materials and plantings necessary for landscape services. The publication will be important in Forest Service Regions 1 (Northern), 2 (Rocky), 4 (Intermountain) and western portions of Region 9 (Eastern). The key clients include State Forestry agencies, USDA Natural Resources Conservation Service staff, extension agents and diagnostic laboratories, university researchers and teachers, commercial tree nurseries, tree health consultants, and non-governmental organizations involved in tree management.