ABSTRACTWild animals have been implicated as reservoirs and even “melting pots” of pathogenic and antimicrobial-resistant bacteria of concern to human health. ThoughEscherichia coliis common among vertebrate guts and plays a role in the propagation of such genetic information, few studies have explored its diversity beyond humans nor the ecological factors that influence its diversity and distribution in wild animals. We characterized an average of 20E. coliisolates per scat sample (n= 84) from a community of 14 wild and 3 domestic species. The phylogeny ofE. colicomprises 8 phylogroups that are differentially associated with pathogenicity and antibiotic resistance, and we uncovered all of them in one small biological preserve surrounded by intense human activity. Challenging previous assumptions that a single isolate is representative of within-host phylogroup diversity, 57% of individual animals sampled carried multiple phylogroups simultaneously. Host species’ phylogroup richness saturated at different levels across species and encapsulated vast within-sample and within-species variation, indicating that distribution patterns are influenced both by isolation source and laboratory sampling depth. Using ecological methods that ensure statistical relevance, we identify trends in phylogroup prevalence associated with host and environmental factors. The vast genetic diversity and broad distribution ofE. coliin wildlife populations has implications for biodiversity conservation, agriculture, and public health, as well as for gauging unknown risks at the urban-wildland interface. We propose critical directions for future studies of the “wild side” ofE. colithat will expand our understanding of its ecology and evolution beyond the human environment.IMPORTANCETo our knowledge, neither the phylogroup diversity ofE. coliwithin individual wild animals nor that within an interacting multispecies community have previously been assessed. In doing so, we uncovered the globally known phylogroup diversity from an animal community on a preserve imbedded in a human-dominated landscape. We revealed that the phylogroup composition in domestic animals differed greatly from that in their wild counterparts, implying potential human impacts on the domestic animal gut. Significantly, many wild individuals hosted multiple phylogroups simultaneously, indicating the potential for strain-mixing and zoonotic spillback, especially as human encroachment into wildlands increases in the Anthropocene. We reason that due to extensive anthropogenic environmental contamination, wildlife is increasingly exposed to our waste, includingE. coliand antibiotics. The gaps in the ecological and evolutionary understanding ofE. colithus necessitate a significant uptick in research to better understand human impacts on wildlife and the risk for zoonotic pathogen emergence.