‘Morgan River’ is the original name of the Cygnet River. The river rises in central Kangaroo Island and meanders in an easterly direction until it enters Nepean Bay, about 5 kilometres south of Kingscote. The first colonial manager of the South Australian Company, Samuel Stephens, arrived in Kangaroo Island on 27 July 1836 on the Duke of York and named the river after its captain, Robert Clark Morgan. At some time later the river’s name was changed to ‘Cygnet River’. It took its new name from the Cygnet, the fifth ship to arrive in South Australia.

Map

Sources:

Geoffrey H. Manning, Manning’s Place Names of South Australia Form Aaron Creek to Zion Hill, (2006), Gould Books, Modbury

http://en.wikipedia.org/wiki/Robert_Clark_Morgan