In the nineteenth century, the colonial territories of California and Hawai'i underwent important cultural, economic, and ecological transformations influenced by an unlikely factor: cows. The creation of native cattle cultures, represented by the Indian vaquero and the Hawaiian paniolo, demonstrates that California Indians and native Hawaiians adapted in ways that allowed them to harvest the opportunities for wealth that these unfamiliar biological resources presented. But the imposition of new property laws limited these indigenous responses, and Pacific cattle frontiers ultimately became...