Starting on Linton Road Wetherby the route is a railway path before it goes through a housing estate and uses an underpass to cross the A1(M).
The old railway viaduct over the River Wharfe was reopened as a cycle path in 2018, this formed a new section of the route from the trading estate to the A659 at Newton Kyme.
[3] A 500 metre cycle path through the trading estate was installed in spring 2020 to fill the gap in the route which had been left when the Wharfe crossing opened.
NCN 665 ends where it meets Route 65 at Askham Bar Park and Ride site.
This section is paralleled to the south by NCN 66, which follows quiet country lanes.