Thankyou!
Coming back to the highway just retrace you’re steps! The on ramp isn’t clearly marked but is obvious and like many along Mexican roads quick ,short and kind of scary!
Incidentally highway 15 D is in pretty good condition all the way to Mazatlan. There are a few rough patches in the right hand lane but when traffic is light you can easily switch lanes and or straddle the potholes!
We made it down this far with no issues other than torrential Rain that made visibility poor!