Several species of dolphins in both isolated and continuous regions exhibit geographic variation in whistles. Although whistles are thought to be learned, possible structural components are exhibited across communities. Whistles from three transient killer whale (Orcinus Orca) groups, Prince William Sound, the Pribilof Islands, and False Pass were compared for spectral and temporal properties. Of 395 randomly selected frequency contours of whistles, there were 32 shape categories of whistles. Overall, whistle shapes from different areas reflect homogeneity, with four whistle shapes comprising 50% of all repertoires. The most common whistle contour shapes were up, down, flat, and oscillatory. Whistles from at St. Paul Island, described here for the first time, had higher fundamental frequencies and shorter durations than whistles from Prince William Sound and False Pass. Surface whistles from St. Paul Island had higher mean frequencies than those recorded at depth with passive acoustics. One identical whistle type was found at both St. Paul Island and False Pass, which suggests the same whales travel between the two areas. The longest whistles and most variable whistles were recorded at False Pass.