The route starts on the A736 by Caldwell Golf Club, whose car park seems to be an extension of the road. Setting off westward, the B776 first skirts the golf course, then climbs into the hills, with the Caldwell Tower clearly visible on the right. On reaching the moors, the road is crossed by the B775.
We continue west across the fields and soon a sharp bend to the right alters our course to a more northerly one. Skirting Barcraigs Reservoir, the road starts to descend, gently at first but then more steeply, into the valley of the Black Cart Water. We enter Howwood along Bowfield Road before a hairpin bend to the left brings us to the road's end at a T-junction on the B787 (pre-bypass A737).