Allowing for about eight years of travel through the wilderness to Bountiful, the Nephites had been about 170 years in the New World. At that point, they were no longer a transplanted Old World colony. From this point on (though probably from much, much earlier), the Nephites were surely a New World culture that had adapted to the climate and foodstuffs and had worked out relationships with the other towns/cultures around them.
While the presence of other established cultures is not described explicitly, the Nephite assimilation or borrowing of physical and perhaps ideological culture from those other peoples runs under the text of the Book of Mormon, just as the religion of Canaan runs faintly but traceably under the Old Testament. (See 1 Nephi, Part 1: Chapter 2, “Introduction to 1 Nephi.”)
Chronology: Enos’s death occurred somewhere in 407 B.C. using January 586 B.C. as the date of the departure from Jerusalem.