Helaman 6:12 states that the people "did raise grain in abundance, both in the north and in the south; and they did flourish exceedingly, both in the north and in the south." Richard E. W. Adams, a leading Maya archaeologist and professor of anthropology at University of Texas, San Antonio relates:
One of the long-standing misconceptions of Maya archaeology has been that Maya civilization existed within dense tropical forest much the same as the environment today. This now appears false (1986:443)
Among the modifications Adams lists that the Maya performed are:
1. Nearly every hillside was terraced.
2. There were raised fields.
3. There were water holes enlarged and new ones dug.
4. Swamps were drained.
5. Water-filled canals were common.
6. Dams conserved water for use in the dry season.
7. Trees were planted forming boundaries.
8. There were large agricultural zones in suburbs with remains of laboriously created gardens (some enormous).
9. Forest existed only in remnants, with stands left for hunting and logging, and selected tree species were left.
[Shirley R. Heater, "Rio Azul Sheds Light on Book of Mormon Subjects," in Recent Book of Mormon Developments, Vol. 2, p. 131]