Rural populations face unique challenges to physical activity that are largely driven by environmental conditions. However, research on rural built environments and physical activity is limited by a paucity of rural-specific environmental assessment tools. The aim of this paper is to describe the development and testing of a rural assessment tool: Inventories for Community Health Assessment in Rural Towns (iCHART). The iCHART tool was developed in 2013 through a multistep process consisting of an extensive literature search to identify existing tools, an expert panel review, and pilot testing in five rural US communities. Tool items represent rural built environment features that influence active living and physical activity: community design, transportation infrastructure, safety, aesthetics, and recreational facilities. To assess reliability, field testing was performed in 26 rural communities across five states between July and November of 2014. Reliability between the research team and community testers was high among all testing communities (average percent agreement = 77%). Agreement was also high for intra-rater reliability (average kappa = 0.72) and inter-rater reliability (average percent agreement = 84%) among community testers. Findings suggest that the iCHART tool provides a reliable assessment of rural built environment features and can be used to inform the development of contextually-appropriate physical activity opportunities in rural communities.