["American Journal of Human Biology, Volume 38, Issue 4, April 2026. ", "\nABSTRACT\nMajor advances in understanding human biology and health have been made possible by long‐term field research projects with Indigenous peoples, whose ecological settings and lifeways are distinct from majority populations in high‐income settings. Long‐term fieldwork is central to human biology, yet much about this research approach remains opaque. This paper considers a single long‐term study—the Shuar Health and Life History Project in Amazonian Ecuador—and discusses how we have navigated practical, political, and ethical challenges of initiating and maintaining a two‐decade long collaborative project with integrative field and laboratory components. By enhancing transparency and offering logistical and ethical insights, our goal is to provide guidance to researchers. We offer three sets of conclusions and recommendations. First, our highly integrative approach allows us to ask important scientific questions and answer them in innovative ways. We recommend investment in broad theoretical and methodological training and study design, as well as a project structure that nurtures students' ideas. Second, a project like ours is extremely challenging to operate, requiring major sustained commitment of time and funding to maintain the fieldsite and laboratories. We recommend that scientists initiating major field projects be cognizant of these enormous costs and challenges, develop supportive relationships among collaborating researchers, and incorporate flexibility and excess capacity. Finally, sustainable long‐term investment in research communities must be prioritized, and the science and outreach efforts require tailoring to local conditions and realities. We recommend that researchers invest deeply in communities, building trust and establishing long‐term relationships that are mutually beneficial.\n"]