The Tangipahoa River channel:
- Is straight in the upland stream area as it flows south to Highway 190, with a sand and gravel substrate;
- Becomes a lowland stream with a muddy substrate south of Highway 190.
The stream bank:
- Has bluffs in the upland areas where the land lies far above the high water of the river;
- Has sandy beaches or gravel areas in streamside deposits;
- Has cypress swamps near the point at which the stream enters Lake Pontchartrain;
- Has lush vegetation, either forest or swampy wetland, lining other areas of the stream bank.
- Is composed of pine forest and pasture lands in the upland area;
- Consists of cypress and tupelo swamp in the lowland area where the stream widens.