- Head of Passes
Head of Passes is where the main stem of the
Mississippi Riverbranches off into three distinct directions at its mouth in the Gulf of Mexico: Southwest Pass (west), Pass A Loutre (east) and South Pass (centre). They are part of the "Bird's Foot Delta", the youngest lobe of the evolving Mississippi River Delta.
The "Head of Passes" is considered to be the location of the mouth of the Mississippi River.
US Army Corps of Engineersmaintains a 45-foot (13.7 m) shipping channel from the mouth of Southwest Pass—20 miles (32 km) downriver from the Head—up to Baton Rouge, the US's furthest inland deep-water port. [cite web
author=Navigation Data Center
month=December | year=2003
title=The US Waterway System—Transportation Facts
The Mouth of Passes is the aggregate of the individual mouths of the passes connected to the Head of Passes, including the Southwest, South, North Passes and Pass a Loutre. [cite web
title=Watershed Assessment, Tracking & Environmental Results System
work=Environmental Protection Agency
accessdate=2006-03-11] While the majority of the discharge of the Mississippi River flows through these mouths, a portion of the river flows out of the
Atchafalaya Rivermouth, and a small portion continues to seep out of the 200 miles (300 km) of the Delta shoreline. [cite web
American Civil War, Head of Passes was the site of several naval battles. The Anaconda Plancalled for a large Union blockadeof the Confederacy, and included plans to control the Mississippi River. This began in 1861with a Union blockade stationed at the Head of Passes. Ships involved in the ensuing conflict at the location include the " CSS Manassas", the "USS Vincennes", and the "USS Richmond". Port Eadsis located at the southern tip of South Pass.
The Head of Passes is the datum from which mileages on the Lower Mississippi River are measured. [cite web
author=Sole, Robert L. "et al"
month=November | year=1999
title=Lower Mississippi River Ports and Waterways Safety System (PAWSS) RF Coverage Test Results
Algiers Point, for instance, is at mile 94.6 AHP (above Head of Passes). Cairo, Illinois, is at mile 953.8 AHP. Mileages downstream from Head of Passes are labelled BHP (below Head of Passes). [cite book
title=Historic Names and Places on the Mississippi River
publisher=Mississippi River Commission
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