Complex sentence: The first European explorer to pass near the site of Coober Pedy was Scottish-born John McDouall Stuart in 1858, but the town was not established until after 1915, when opal was discovered by Wille Hutchison.
Split into simpler sentences: The first European explorer to pass near the site of Coober Pedy was Scottish-born John McDouall Stuart in 1858. The town was not established until after 1915, when opal was discovered by Wille Hutchison.