OYSTER BOTTOMS IN MATAGORDA BAY. 11 



lies in the direction of the coastal trend, and its waters are separated 

 from those of the gulf merely by a narrow sandy peninsula, which 

 the erosion of storms periodically converts into an island. Pass 

 Cavallo, the entrance to the bay, about 125 miles southwest of Gal- 

 veston, lies at the extreme southwestern corner, and carries in its 

 channel a depth of about 10J feet at extreme low water. At the time 

 of the survey this was the only direct communication between the 

 waters of the bay and the gulf, but prior to the summer of 1904, 

 when it finally closed, Mitchells Cut, an opening of widely fluctuat- 

 ing depth and width, admitted salt water to the extreme upper part 

 of the bay, and in the spring of 1905 an effort was being made, in the 

 interest of the oyster industry, to open a channel to salt water from 

 the head of Browns Bayou. From Pass Cavallo to the head of the 

 bay is a distance of about 50 miles, and from the pass to Sand Point, 

 at the mouth of Lavaca Bay, is about 13 miles. 



AREA AND SHORE LINE. 



The southwestern part of Matagorda Bay is about 12 miles wide, 

 but at Palacios Point it abruptly narrows to about 4J miles, with an 

 average slightly less than this as far as Dressing Point, where there 

 is another abrupt contraction to about 1^ miles thence to the head of 

 the bay. The total area, exclusive of Lavaca, Karankaway, and 

 Tres Palacios bays, which are contiguous to the wide southwestern 

 part, is about 310 square miles, the area covered by the survey above 

 the point of Half Moon Reef approximating about 140 square miles. 

 The northwestern or prairie shore is almost unbroken, save at the 

 mouths of the Colorado River and several creeks, but the peninsula 

 littoral is extremely irregular, with numerous muddy bayous, which, 

 especially below Dog Island Reef, in many cases head at the foot of 

 the sand dunes which skirt the outer coast. 



AFFLUENTS. 



The principal fresh-water affluent is the Colorado River, which rises 

 on the borders of the Staked Plains and, draining a large basin 

 along its course of from 700 to 800 miles, discharges above Dog 

 Island, about 2 miles west of Matagorda. A considerable, if not the 

 preponderating, flow now passes through Buffalo Bayou, close to the 

 town, and the river's western mouth, shown on previous surveys, has 

 become obliterated by the deposit of silt. Mad Island, Little Boggy, 

 Big Boggy, Live Oak, and Caney creeks also at times carry considera- 

 ble volumes of fresh water, the last-named stream entering the 

 extreme head of the bay through an artificial channel. It appears to 

 have entirely lost its original direct connection with the gulf. 



