Pokemon Heart Gold and Soul Silver - Walkthrough - Mt. Silver Pokemon Heart Gold and Soul Silver: Walkthrough - Mt. Silver
Go up, there is a Pokemon Center here for your convenience. If you have a Pokemon with CUT, then go down the stairway to the right, CUT the tree, and enter the house. Inside, talk to the girl, you will get TM47 STEEL WING.

Exit the house, continue right, and pick up TM35 FLAMETHROWER. Now head back up the stairway to Mt. Silver.

Now go south, down the left stairway, SURF across the water, go across the grass, and up where the item is. Pick up the REAPER CLOTH.

Now go back to the Pokemon Center. When you are prepared to enter, hop the ledge to the left, and go into the cave.
This walkthrough was written by MKaykitkats, used with permission.