Things You'll Need
Instructions
Walk southwest from the Indigo Plateau or northwest from Victory Road to reach Route 28. At the end of the road, go north to enter the cave. This is the first floor of Mt. Silver.
Walk around on the first floor to trigger a random battle. Steelix is one of six Pokemon that may appear during a battle. Steelix appears in battle 20 percent of the time, with only Quagsire appearing more often.
Use fire or water moves to attack Steelix when it appears in battle. Steelix is weak to these move types. Steelix also has low special defense, so special attacks, like psychic moves, work well.
Damage Steelix until its health bar turns red. Throw Poke Balls to catch Steelix. Ultra Balls and Dusk Balls work well.