When the incipient foredune reaches a height of roughly 0.5 m (1.5 ft), the dune itself becomes an obstacle to the wind. The dune continues to grow as wind-blown sand from the beach is deposited on the dune. Vegetation such as American beachgrass (Ammophila breviligulata) grows up through the deposited sand to anchor the dune sand and cause further deposition.

Foredunes of 1-1.5 m height (3-5 ft) may be tall enough to trap all the wind-blown sand from the beach. At this point, inland dunes or structures do not receive wind-blown sand from the beach.