In 2013, the breed was awarded protected status by the European Commission.
The images look at the relationship between the animals, the fell farmers who breed them and the landscape.
A Portrait of Lakeland opens at Penrith's Rheged Centre on Saturday.
When they are born, pure bred Herdwick lambs are usually black and often have tips of white on their ears.
Here the sheep are being herded down the mountain with the farmer and his dog.
Their heads and legs then become white as they grow older and their fleece takes on a colour from blue-grey to light grey.
