|Location Map ( geo)|
|From:||East Gordon (NT679441)|
|Distance:||6 miles (9.7 km)|
|Meets:||A6105, A6089, B6397|
|Route outline (key)|
The C90 starts on the A6105 in the middle of nowhere, about half a mile east of East Gordon, and heads south east at first before turning south west to pass Middlethird. The route continues south west across the Eden Water to reach the A6089, with which it multiplexes south for a short distance. Continuing westwards, the route climbs steadily up the hill at Fans, before dropping a little to meet the B6397 near Purvishaugh.