Early sunlight slanted into the tree house. The cool breezesmelled of wild grass.

"Oh, man," said Jack. "These are neat clothes."Their jeans and T-shirts had magically changed. Jack had on abuckskin shirt and pants. Annie wore a fringed buckskin dress.

They both wore soft leather boots and coonskin caps. Jack'sbackpack was now a leather bag.

"I feel like a mountain man," he said.

"All you're missing is a mountain," said Annie. She pointedout the window.

Jack and Teddy looked out.

The tree house sat in a lone tree in a vast golden prairie. Thesun was rising in the distance.

Wind whispered through the tall yellow grass. Shh--shh--shh,it said.

"We need a gift from the prairie blue," said Jack.

"I bet that means the sky," said Annie, looking up.

"Yep," said Jack. The sky was growing bluer as they watched.

"But how are we supposed to get it?""Just like last time," said Annie. "We have to wait till someonegives it to us.""I don't see any sign of people out there," said Jack.

He opened their book and read aloud.

The Great Plains are in the middle of the United States. Beforethe 20th century, this vast prairie covered nearly a fifth ofAmerica's land. Some called it "an ocean of grass."Jack pulled out his notebook.

"Come on," said Annie.

She picked up Teddy and carried him down the ladder.

Jack quickly wrote:

Great Plains - lots of land"Wow, this is like an ocean of grass," Annie called frombelow.

Jack slipped the Great Plains book and his notebook into hisleather bag and climbed down.

When he stepped onto the ground, the grass came all the wayup to his chest. It tickled his nose.

"Ah-ah-CHOO!" he sneezed.

"Let's go swimming in the grass ocean," said Annie.

She started off with Teddy under her arm. The wind blewgently as Jack hurried after her. All he could see was rollingwaves of grass.

They walked and walked and walked. Finally, they stopped torest.

"We could walk for months and never see anything but grass,"said Jack.

Arf! Arf!

"Teddy says there's something great up ahead," said Annie.

"You can't tell what he's saying," said Jack. "He's just barking.""I can tell," said Annie. "Trust me.""We can't walk all day," said Jack.

"Come on," said Annie.

"Just a little farther." She started walking again.

"Oh, brother," said Jack.

But he kept going through the tall, rippling grass. They wentdown a small slope, then up a small rise. At the top of the rise,Jack froze.

"Wow, that is great," he whispered.

"Told you," said Annie.