A number of tribes split up or were combined as tribes were settled on various reservations.a fair amount of Native American nations were, if not annihilated, diminished and forced to relocate, often losing their identity.
we still have Cherokee, Iroquois and Navajo nations (among others) but they are small subject peoples.
Aztec, Inca and Maya were decimated and lost their political identity.
At the present time there are 573 federally recognized tribal governments in the USA that have functions vaguely analogous to state governments, and more groups eek federal recognition.
List of Federal and State Recognized Tribes
As I remember, the Yahi Indians in California suffered devastating losses in about a dozen massacres by local civilians and the last dozen or so hidden survivors most l died of natural causes until the last one joined white society in 1911 and died a few years later.
In the period from about 1848 to 1870 or later the California state government and the local governments in California usually had genocidal policies toward the California Indians which is why some sources write about "the California Genocide".
Various North American Indian tribes suffered from terrible epidemics of old world disease that killed large percentages of their populations repeatedly over a few centuries between about 1500 and about 1900 before their populations began to recover.about 1900. So the extreme natural declines in the populations of various tribes should not be confused with their war casualty figures.
So it is possible, but not certain, that some nations, tribes, and groups in the USA had percentages of their populations killed in various conflicts that were similar to the percentages of deaths that several European countries suffered in World war II or World War I, or even to what Paraguay suffered in 1864-1870.