In 1983 they started excavating in the bottom of the gravel pit.
The subdrift system requires a smaller amount of narrow work in excavating the necessary haulage roads, and is therefore better adapted to hard ores in which such narrow work is expensive.
The volunteers assist in releasing the hatchings and excavating the nests to determine the hatching success rate.
Like all salmonids, grayling spawn on clean gravel, excavating a small redd in the gravel in which their eggs are laid.
Egyptians - The Theban Mapping Project Homepage of the group excavating the largest tomb found in Egypt.