Biggar Gap is a flat-floored, steep sided valley floor, just below 200m; up to 1km wide, and over 8km long. It is drained today by the artificially straightened Biggar Burn which is much too small to have cut such a deep, wide valley. It is believed to have been cut by what is now the Upper Clyde, on it's way to join the River Tweed, before it was captured by what is now the Lower Clyde. The Biggar Gap is an area so flat that it allows links between the Tweed and Clyde catchments and today there are three wetland areas that drain on their west into the Clyde and on their east into the Tweed. It has been reported that Salmon that enter the Coulter Burn from the Biggar Water can at high water levels end up crossing into the Clyde and spawning, producing Salmon Parr far upstream of the Falls of Clyde that are a complete block to Clyde fish
Cache is a bison.
Well Done to thistlecampers for the FTF!