Simplify the following text for a Grade 6 native English-speaking person.
Original: Discovered by Edward John Eyre in 1839 , for the following twenty years it was believed that Lake Torrens was an enormous horseshoe-shaped saltpan encircling the northern Flinders Ranges and blocking any path to the interior .
Simplified: Lake Torrens was discovered by Edward John Eyre in 1839 . For many years it was believed that Lake Torrens was a large horseshoe-shaped salt lake in the northern Flinders Ranges .