The incorporation of the region north of the Alpine divide and its foreland into the Imperium Romanum initiated major changes in economic and social structure and in everyday life in the newly-founded province of Raetia. Controversy exists, however, about the continuity of local La Tène traditions into early Roman times, since the archaeological evidence recorded to date tends to give the impression that the northern Alpine foreland was largely unpopulated at the time of the Roman conquest in 15 bc. However, ongoing excavations in this region are gradually enhancing the archaeological visibility of this transitional phase. Compared to early Roman provincial populations settled along the Via Claudia Augusta and its hinterland, a culturally unique community stands out: the Heimstetten group. This group is located in the eastern Raetian hinterlands and dates to around 30–60 ad. Its building tradition, settlement structure, and burial customs show close affinities with the La Tène culture, thus suggesting continuity in autochthonous culture at the time of the early Roman occupation. Since faunal remains can potentially act as cultural markers, additional insights can be gained from a spatial-temporal analysis of livestock composition and breeding practices. The results presented here clearly show that, during the Iron Age, marked regional differences in species composition are visible, implying the possibility of distinct developments during early Romanization. In addition to evaluating faunal developments in the study area between c. 100 bc–100 ad, the issue of cattle breeding—traditionally the mainstay of livestock economies in many regions and especially in the Munich Gravel Plain at least since the Bronze Age—is addressed in greater detail.