4 Tex. Admin. Code § 41.22
Quarantined areas are as follows for Cameron County. Beginning at a point where the Hidalgo-Cameron County line intersects U.S. Highway 281, following U.S. Highway 281 in an easterly direction to where it intersects Boca Chica Boulevard, approximately 26.2 miles; thence, following Boca Chica Boulevard in an easterly direction to where it becomes Boca Chica Road and continuing in the same direction on Boca Chica Road to where it intersects a drain ditch, approximately 9.5 miles; thence, following this drain ditch in a northerly direction to where it intersects the Brownsville Ship Channel, approximately three miles; thence, following the Brownsville Ship Channel in a northeasterly direction to where it enters the Gulf of Mexico, a distance of approximately 17.5 miles.
4 Tex. Admin. Code § 41.22