Established in 1938 as the National Arborist Association, today's Tree Care Industry Association is a trade association of more than 2,000 commercial tree care firms and affiliated companies.

NATS serves the needs of their clients by engaging on an individual level. Through their training and educational programs, they share their wealth of knowledge, resources, and tools to increase safety and efficiency in the workplace.

Through research, technology, and education, the International Society of Arboriculture (ISA) promotes the professional practice of arboriculture and fosters a greater worldwide awareness of the benefits of trees.