The Book of Mormon only gives us a few concrete numbers to help us understand population sizes. We have a good idea of the size of Lehi’s founding party, but we have no idea of the size of the Mulekite or Jaredite parties. We have a few abstract indications, but no concrete demographics, representing the overall size of any populations during their histories until near the end of the Jaredite record where multiple millions of the Jaredites are killed and near the end of the Nephite record where 230,000 Nephites are killed.
When you relate these numbers to the lands proposed in our model of the Book of Mormon lands in Baja California and the North American Southwest, what you will find is that the numbers mentioned for the millions of the Jaredites and the 230,000 Nephites are both mentioned in relation to greater North American Southwest rather than actually being the population of the Baja peninsula. This makes the population numbers quite vague for the peninsula.
I like the writeup that P. L. Simiskey did for nephiproject.org, but since our model suddenly has the ability to pull extra Nephites from the Land Northward who may not have been involved in battles before Cumorah, his writeup isn’t geared especially to tell the story presented in our model. In our model you must consider the peninsular population to relate to some population references without relying on the Northward population before Cumorah.
Baja historians’ estimates of the indigenous population of the peninsula vary widely, but a safe estimate seems to be about 50,000 people. Please keep in mind that we also propose that the climate of the peninsula was much wetter than conditions at the time of Spanish contact and the wetter climate might have supported a much larger population.