D&C 54:8
8 And thus you shall take your journey into the regions westward, unto the land of Missouri, unto the borders of the Lamanites.
There is a debate among LDS apologist about the actual geography of the Book of Mormon. Traditionally it has been accepted by LDS that the entirety of the American continents represents the location of the Book of Mormon. Recently there has been a growing voice that the events in the Book of Mormon happened in a limited geographical area (most likely in Central America). Those of the latter opinion claim that there are actually 2 Hill Cumorahs, one in New York and another mentioned in the Book of Mormon. Traditionally it has been believed by LDS that all of the American Indians represent the descendants of the Lamanites. Those who hold to this limited geographical view believe that the Lamanites have all but died out and Native American people have a genetic make up largely made up from those that migrated over the Bering Strait.
Doesn’t this verse from the Doctrine and Covenants show that at the very least that Missouri hosted some or all the events of the Book of Mormon. Or at least show that the Lamanites live in Missouri or did at one time? Interested to hear from LDS who understand this scripture and the debate better.
LDS & Evangelical Conversations 
Native Americans were called Lamanites by the LDS pretty much from the beginning. You don;t hear it that much anymore, but you used to a lot more, especially whent he Church was more of a mountain West phenomenon than the semi-global presence it is now.
I’m no history buff, and I haven’t looked at the full context of this reference, but there’s a couple of possibilities here. As indicated by Kullervo, it could have simply been a reference to a population of Native American’s at the time of the revelation, or it could indicate that Missouri is the farthest east the nations of the lamanites extended in the BoM times.
Either way, it seems to support my understanding that the NY Hill Cumorah was a namesake. Moroni traveled in fear for his life for many years (upwards of 30 as I recall) after the last battle, so it doesn’t make sense to me that the place he buried the plates was the same place the final battle took place.
Your explanations make sense to me, but I don’t think they would work with those who promote the LGT (limited geography theory). It’s my understanding that they are saying that the bloodline of the Lamanites was completely extinct by the time Joseph Smith came on to the scene and that the events of the Book of Mormon did not take place in North America.
can anyone who’s really swayed by the LGT chime in?
I don’t know of any LDS who would say that there are no lamanites in present times. My understanding is that there is a high probability that bloodlines have been mixed, but not removed completely.
And I think there are very few dealings recorded in the BoM compared to all that happened in that 1000 year history. Just because the Nephite/Lamanite conflict may have occured in a limited geography does not mean that there weren’t populations that expanded their territory in other directions.
Well, there’s the DNA evidence (or lack thereof)…
DNA evidence indeed. Since we now have a good knowledge of genetics, and the complete human genome, it can be said, and has been shown, that the American Indian bears no genetic resemblance the the Semitic race.