What is the MKARNS?
Four hundred and forty-five miles long with 18 locks and dams, the McClellan-Kerr
Arkansas River Navigation System (MKARNS) is a reliable, year-round waterway
into the Southwest. Essentially a series of navigation pools connected by locks,
the waterway enables vessels to overcome a 420-foot difference in elevation
from the Mississippi River to the head of navigation at Catoosa, Oklahoma.

The navigation system was designed for ease of navigation by multi-barge tows, 
with ample channel and lock dimensions and bridge clearances. Necessary dredging
 is done promptly, and the channel is open year round. The locks and dams are 
operated 24 hours a day by the Corps of Engineers;the Coast Guard maintains 
the channel markers and other navigation aids.

Since barges are one of the most energy-efficient forms of transportation, there
 is a resurgence of interest in shipping by inland waterway. Many types of commodities
are now shipped on the waterway, and there is adequate capacity for future 
development. International trade is aided both by good access to foreign ports through
 the Gulf of Mexico and by the existence of two foreign trade zones on the waterway. 
The waterway will accommodate a variety of barges and towboats; and there is good 
access to road, rail, and air transportation.

The waterway has five major publicly developed ports and numerous privately 
developed facilities. A considerable amount of land suitable for development is 
available at the ports and in other areas. People interested in expanding, locating, 
or relocating along the McClellan-Kerr will find that there are many organizations 
able to advise and assist on development projects. The Corps issues permits 
for a wide variety of projects and can be especially helpful in enabling a potential 
developer to understand how the characteristics of the waterway may affect a 
particular site.

Location of the MKARNS
The Arkansas River is one of the Mississippi's largest tributaries. It flows
1,450 miles from the Rocky Mountains in Colorado, through the Royal Gorge,
on through Kansas, Oklahoma, and Arkansas to its confluence with the
Mississippi River. While it is convenient to think of the McClellan-Kerr essentially
as synonymous with the Arkansas River, this is not in fact the case. The
downstream portion of the Arkansas River is the major component of the
445-mile-long system, but in all there are four distinct segments of the waterway: 

WHITE RIVER ENTRANCE CHANNEL. The McClellan-Kerr begins in Arkansas at mile
599 on the Mississippi River, about half way between New Orleans and St. Louis,
using the first ten miles of the White River as its entrance channel. 

ARKANSAS POST CANAL. The next nine miles of the waterway are totally manmade;
a navigation canal connecting the White River with the Arkansas River. 

ARKANSAS RIVER. For the next 377 miles, through Arkansas and into Oklahoma,
the McClellan-Kerr and the Arkansas River are one and the same. 

VERDIGRIS RIVER. In Oklahoma the waterway leaves the Arkansas River once
again, at Muskogee, and follows the Verdigris River north for the last 50 miles to
the head of navigation at Tulsa's Port of Catoosa, 445 miles from the Mississippi River.

Navigational Capabilities
Channel depth: 	9 feet or more
Channel width: 	mostly 250 ft. - 300 ft.
Bridge clearances:	Horizontal--generally 300 ft.or more
 		Vertical--52 ft. or more
Lock size: 	110 ft. x 600 ft.
Normal current velocity range:  2-4 m.p.h.
Size of tow accommodated: 	8 jumbo barges without double lockage
			more than 8 with double lockage using tow haulage
 

What is tow haulage?
Tow haulage is a procedure for drawing barges through a lock by using equipment 
on the lock itself to minimize the maneuvering of a towboat when a tow exceeds 
the length of the lock.

Since the locks on the waterway can hold only eight jumbo (35 ft. X 195 ft.) 
barges plus a towboat, when a tow with a larger number of barges reaches a 
lock, the towboat must split the tow into units or "cuts" that fit the lock.  
The towboat must lock through with the first cut, push it out of the lock, 
and then lock back through to get the second cut of barges. Tow 
haulage equipment on a lock, on the other hand, can pull the first cut 
through by itself, so that the towboat can stay in its original pushing 
position and lock through with the second cut.

Lock operation for oversize tows is more efficient with tow haulage equipment.
Towboats are used more expeditiously, and shippers can take advantage of 
the economy of large tows. Larger tows represent a potential for significant 
cost reduction for both shippers and their customers. Tow haulage equipment 
has been installed at twelve locks on the McClellan-Kerr in Arkansas.

Locks on the MKARNS
There are 18 locks; 5 in Oklahoma and 13 in Arkansas.
All lock chambers are 110-feet wide by 600 feet long.