Wordsworth writes “Middleham” when he seems to mean “Middleton.” Both places are situated
in North Yorkshire, but High Force is located nearest Middleton-in-Teesdale.

The major north-south highway in Britain, running from London to York and on to Edinburgh.
Today the A1 follows essentially this same route.

Wordsworth presumably makes this assumption because roughly 85% of Britons lived south of the Lake District in the first half of the nineteenth century.