I got out for a short local ride in the failing light of yesterday evening. I rode three local trails, one of which I'd ridden before, plus two other new ones. I'm building up a collection of local trails, so that I can eventually link them into an uber-Darlington-ride.
I started out along Patches Lane bridleway, from Whesso Road to Coatham Lane, which I'd ridden before. It starts off as a gravelly track, but eventually becomes a mud track. It was pretty muddy on the top, but the mud was fairly hardened by the recent dry weather, so wasn't too bad; there were hoof-prints about 8 inches deep in places, however, so it could be bad in wet weather. This is about 2km long climb/decent. Tyre marks showed someone else had ridden it recently.
To avoid the grassy slog on the way home, I took a short bridle way from nearby, to the A167. This was just a short 1km track, but it avoided a bit of road-time.
From the A167, I used the minor road through Brafferton to loop around the Coatham Mundeville again, and rerode Patches Lane in reverse, though there are a couple of bridleways from Brafferton itself which link in with those behind Barmpton village and Salter's Lane, and eventually up as far as Sedgefield and Trimdon. In fact, there are some very long stretches of bridleway out that way.
From Newton Aycliffe, I've found a few BWs on the map, leading over to Shildon, and there are some interesting looking BWs west of Shildon/south of Bishop Auckland, which could be linked to the disused railway lines to create an almost off-road route to Durham.