Complex sentence: Around 1958, a local business owner, Alex Madonna purchased a ranch on a portion of the slopes of Cerro San Luis Obispo, and constructed Madonna Inn at its base, which is how the mountain also came to be called "Madonna Mountain".
Split into simpler sentences: Around 1958, a local business owner, Alex Madonna purchased a ranch on a portion of the slopes of Cerro San Luis Obispo, and constructed the now famous Madonna Inn at its base. This is how the mountain also came to be called "Madonna Mountain".