Travelling from GM to Camaar went too far

I was returning from GM heading for the Camaar turnoff.  I was riding a horse.  I had traveled a couple squares off road to see if there were other attacks, then went back to the road and continued west.  
I hit the left arrow and nothing happened.  Tried again and suddenly I was near the end of the forest leading to Azetyth.  I don't know the stamina before, but it was 169 afterward, so I'd guess I lost 20 stamina.