River Tywi these fish to over in weight. In summer and autumn there is also a substantial run of Atlantic salmon ("Salmo salar"). In May the Tywi has a run of the rare and protected twaite shad ("Alosa fallax") and allis shad ("Alosa alosa"). The Tywi also contains brown trout, eels, pike, and a variety of small fish species, and is home to brook lampreys, river lampreys and sea lampreys. The Tywi has the distinction of having accidentally produced by far the biggest fish ever taken on rod and line in fresh water in Britain. This was a sturgeon ("Acipwienser sturio") weighing
Fox River (Fish River tributary) tributary of Fox River, known as Blue Rock Creek. I X L Gulch is a small tributary which heads about a mile southwest of Fox River. Slate Creek is another tributary, from the south. Along Fox River, about south of Council, there are several dikes of greenstone that under the microscope are found to be slightly altered diabase. They consist of labradorite and olivine phenocrysts in a groundmass of plagtoclase, augite, and biotite. Some greenstone masses which appeared to be slightly altered tuffs were found in the divide between Fox and Solomon rivers. Fox River (Fish River tributary) Fox River