Complex sentence: Some researchers estimate that there are only 1,000 to 2,000 adult snakes of the subspecies "T. s. tetrataenia" remaining, however, the full extent of the snakes habitat has not been fully documented and many snakes may utilize creeks and other waterways that are currently unexplored.
Split into simpler sentences: Some researchers estimate that there are only 1,000 to 2,000 adult snakes of the subspecies "T. s. tetrataenia" remaining. However, the full extent of the snakes' habitat has not been fully documented, and many snakes may utilize creeks and other waterways that are currently unexplored.