The objective of this dissertation was to examine factors that contributed to the weight and behavioral changes among rural women and their social network members within the context of a multilevel community-based intervention trial, Strong Hearts, Healthy Communities (SHHC). Given that rural populations in the United States disproportionally experience poorer health outcomes than others and multilevel behavior change interventions are extremely limited in rural communities, this dissertation provides timely insights on the successes and lessons learned in promoting physical activity and healthy eating among rural women. Chapter 1 reviews the barriers faced by rural women to engage in physical activity and healthy eating at various social ecological scales and introduces the theoretical framework used for this dissertation. Chapter 2 provides an overview of the SHHC intervention trial. Chapter 3 examines the environmental conditions that maximized rural women’s physical activity when participating in SHHC. Results suggest that SHHC helped rural overweight and obese women living in communities with less walkable destinations to overcome environmental barriers to physical activity while rural women living in more walkable communities did not change their physical activity significantly. Chapter 4 explores mediators of a multilevel behavior change intervention trial that led to positive behavioral changes among rural women. We found that the SHHC intervention increased participants’ perceived social support from friends regarding physical activity and healthy eating. Participants' improved social support from friends marginally mediated the intervention effects for participants’ increased walking time. Chapter 5 investigates whether a rural behavior change intervention would generate beneficial effects among participants’ social network members. Among social network members who perceived having a very close relationship with trial participants, those associated with intervention group participants lost more weight and decreased BMI more than those associated with the control group. Actual spatial closeness did not modify any of SHHC’s ripple effects. Taken together, this dissertation provides important insights on the mechanisms that contributed to rural women and their social networks members’ weight and behavior changes in the context of SHHC. Findings have informed modifications of the SHHC program and future dissemination.