Instructions
Enter the center entrance to Mount Mortar along Route 42. The other openings can be used as exits later on after retrieving Tyrogue from Kiyo. You enter Mount Mortar on the first floor, or 1F. Use the Surf ability to travel on the water on either side of the entrance and head toward the top of the screen. Use the Waterfall ability to climb the waterfall and continue heading toward the top of the screen. In the center of the water along the top of the screen is a landing area and an opening in the cave wall. Enter the cave opening and take it to the Upper Cave room.
Use the set of steps to your right to climb to the top of a plateau. Drop down off the ledge along the top side of the plateau. Walk toward the left side of the screen and use Surf to travel directly across the water toward the top of the screen. Return to land and walk toward the right side of the screen until you reach the next body of water. Use Surf to go across this water toward the top of the screen. Take the stairs to the top of another plateau and drop off the top-side ledge. Walk toward the left side of the screen until you reach a ladder emerging from the ground. Use Surf to go around the ledge keeping you from the ladder. Take the ladder to the Lower Cave room.
Go right down the steps. Continue right and then turn to the bottom of the screen at the end of the hall. Walk down-screen and go up the first stairs toward the right. Drop off the right-side ledge and use the stairs at the top of the screen. Travel to the right and take the first route toward the bottom of the screen. Continue along the ridge line and take the first staircase down. Use the ladder to enter room B1.
Go down the first set of stairs and turn to the right side of the screen. Go down the long staircase toward the right-hand side of the screen. Walk toward the top of the screen to face Kiyo. Kiyo's Pokemon are susceptible to Flying and Psychic-type attacks. To exit the cave, use an Escape Rope or travel back up the stairs, then down the other staircases toward the bottom of the screen. Use Surf to continue across the water toward the bottom of the screen. Take the ladder near the bottom of the screen to the entrance on level 1F.