Wind blows through coastal dunes, forming a depression between the foredune and the backdune. This area is called the trough. The trough often fills with groundwater causing interdunal ponds where many organisms survive in this more stable habitat. EXPLORE: Visit a trough at Hoffmaster State Park in the Summer or Winter.

Just behind the trough is the backdune. The backdune is usually forested and provides shade to its inhabitants. The backdune provides cool temperatures and moist soil adequate for many plants and animals. EXPLORE: Visit a backdune at Hoffmaster State Park in the Summer or Winter.