The lake is vaguely pear shaped .
The lake has a maximum length of 64.3 km ( 40.0 mi ) with a mean width of 20.1 km ( 12.5 mi ) .
The lake is vaguely pear shaped and has a maximum length of 64.3 km ( 40.0 mi ) with a mean width of 20.1 km ( 12.5 mi ) .