This article is the first in a series of three that describes the development and delivery of the Environmental Health and Land Reuse (EHLR) Basic Training and the first pilot of the EHLR Immersion Training. The EHLR Basic Training is based on the 5-step Land Reuse Model from the Agency for Toxic Substances and Disease Registry (ATSDR). Through a collaboration with the National Environmental Health Association (NEHA), we developed the EHLR Basic Training in two modalities: virtual/live (maintained by ATSDR) and online/asynchronous (maintained by NEHA). The modules include: (1) Engaging With Your Community, (2) Evaluating Environmental and Health Risks, (3) Communicating Environmental and Health Risks, (4) Redesigning With Health in Mind, and (5) Measuring Success: Evaluating Environmental and Health Change. From June 2019-August 2022, ATSDR and NEHA delivered 10 EHLR Classroom Basic Trainings, launched the EHLR Online Basic Training, and developed the EHLR Immersion Training. We piloted the EHLR Immersion Training in July 2022, March 2023, and July 2023. Our participants included science, technology, engineering, and mathematics (STEM) students from Dine College who were in a Summer Intern Program; tribal environmental professionals; NEHA members in environmental health careers; and environmental professionals, students, and community members who were engaged in environmental work or environmental justice. We have learned that individual training modules can be used for specific learning needs among our participants. Perhaps more importantly, we have learned that undergraduate students and community members can and should be engaged in EHLR Training. The results of the evaluation and longterm follow-up of the EHLR Training will be presented in the second and third articles in this series.