It was as if they were looking down upon a sea of sand, and it was easy to imagine it the bed of some old, vanished ocean, as scientists tell us the Bad Lands actually are.
For half an hour the horses toiled up the steep slope, first to the right, then to the left, but always rising until at last they came suddenly out upon a level plain, entirely surrounded by towering cliffs, except for the narrow break through which they entered.
“The crater of an old volcano!” cried Dick. “That’s what this place is sure.”
“So I have been informed,” replied Doctor Dan, with his usual gravity.
“Where’s the lake?” asked Charley.
“Just around that bend in the cliffs,” was the reply. “This sink is double, as you may say. The wall runs pretty near through the middle of it. One half is dry and the lake fills the other half. We shall see it in a minute now.”
They rode on and soon turned the corner of the dividing cliff.
A broad stretch of water now lay before them. The lake was many times longer than the dry half of the old crater.
Its surface was perfectly placid and the water seemed to give out a strange, sulphurous odor. The shores were broken by projecting points of rocks, which cut up the lake into many small coves.
“Now, where’s your Plesiosaurus?” exclaimed Charley. “Let him show himself. He’s got an audience that will appreciate him, you bet.”