Level 36.
Pineco will be able to evolve at Level 31.
pineco --lvl.31--> forretress
Pineco evolves into Forretress at Level 31.
pineco evolves at lv.28
level 31
it evolves from pineco at level 31
Level up a Pineco to level 31
Polywag evolved into Poliwhirl at level 25, an then into Poliwrath with a Water Stone.
Evolve a Pineco at level 31. Pineco can be found by Headbutting certain trees.
Lvl 31
Outside of Mt.Silver.
To obtain a Forretress, after obtaining a Pineco train the Pineco to level 36. Use the Ultimate Training Method. Give Pineco the Exp. Share and battle Red with Pineco in your party.