On the far side of a warm, whispering valley, where golden grasses bowed in the evening breeze, lived a family of dinosaurs beneath a cliff shaped like a sleeping giant’s back.

There was Amaru, a gentle, broad-footed Apatosaurus with a long neck and a patient voice. There was Sora, who knew every kind of fern by its scent. And there were their two young ones, Niko and Marisol, who had bright eyes, sturdy tails, and a great interest in going places they had not been told to go.

Their home was a nest of smooth stones, woven reeds, and soft moss beneath three old umbrella trees. Behind it ran a little brook that sang over pebbles. Ahead of it spread a wide landscape of humps, curves, pools, and sandy walls.

Long ago, before Amaru’s grandparents’ grandparents had even hatched, a mighty river had rushed through the valley.

It had twisted and turned, pushed and pulled, carved deep bends into the earth, and left behind its winding shape when it moved away. Now the ancient river was gone, except during the rainy season, when water sometimes remembered its old path and came rushing back.

The old riverbed was not flat like an ordinary meadow.

It was a maze.

There were crescent-shaped hills called oxbows, where reeds grew tall and silver. There were dry channels filled with round black stones. There were cliffs of striped mud, baked hard by the sun. There were ponds shaped like moons and pools hidden beneath curtains of willow leaves.

And beyond all that, near the blue mountains, was a patch of rich, green land where Sora dreamed of making a new home.

“Our nest is getting crowded,” she said one sunny morning as Niko and Marisol bumped into each other while trying to reach the berry bowl.

“I did not bump,” said Niko.

“You bumped with your whole tail,” said Marisol.

“I was turning.”

“You were turning very loudly.”

Amaru smiled. “It may be time to find a place with more room.”

Sora looked toward the distant green patch. “There are young trees there, fresh ferns, and a spring. But to reach it, we must cross the old river country.”

Niko’s eyes grew round. “The Maze of Bends?”

“The very one,” said Amaru.

Marisol gave a small shiver, though she tried to make it look like she was only stretching. “Is it dangerous?”

“It can be,” said Sora. “But danger is not the same as a reason to stay still. We will travel carefully. We will listen to the land.”

So the next morning, while the sky was pink as a seashell, the family set out.

Amaru carried bundles of reeds and their precious smooth nesting stones in a woven sling across his back. Sora carried seeds from the old umbrella trees, wrapped in broad leaves. Niko had been given the important job of carrying a basket of dried fruit.

Marisol had been given the equally important job of carrying nothing at all.

“You must keep your eyes open,” Sora told her.

“I can carry something too,” Marisol said.

“You can carry our map in your mind,” said Amaru. “Notice the turns. Notice the smells. Notice the places water might go.”

Marisol stood a little taller. “I can do that.”

They walked through tall grass until they came to the first bend of the ancient river.

It was a great dip in the ground, wide and curving, with steep walls on both sides. In its bottom grew thorny bushes and purple flowers. The far edge seemed close, but the way down was slippery.

Niko peered over the edge. “We can just climb.”

Amaru looked at the crumbly wall. “Can we?”

Niko tested it with one toe. A clump of dry mud broke away and bounced all the way down.

“No,” he said quietly.

Sora lifted her nose. “I smell damp earth to the east. The old river may have left a gentler slope there.”

So they walked along the rim, past tall grasses where little lizards flashed like green leaves. At last, they found a slope made of packed sand and roots.

As they descended, Marisol noticed little holes in the side of the bank.

“Who lives there?” she asked.

Out popped three fuzzy heads.

“River-mice,” squeaked one.

“We live in the old walls,” squeaked another.

“The walls keep us warm when the wind comes,” said the third.

Niko looked at the steep banks and then at the little mice. “But what if the rain comes?”

“Then we climb through our tunnels,” said the first mouse proudly. “The old river made the walls, and we made homes inside them.”

Marisol tucked that thought into her mind.

The family crossed the bend and climbed out by the gentler slope. By noon, the sun was high and bright. They reached a long stretch of cracked mud with strange wavy lines pressed into it.

“Look,” said Niko. “Footprints!”

They were huge footprints, much larger than Amaru’s, pressed deep into the old mud.

Sora studied them. “They are very old. Perhaps from a herd that traveled here when this was still a riverbank.”

Marisol placed her foot beside one print. Her foot fit inside it three times.

“Do you think they found a home?” she asked.

“I think,” said Amaru, “they made many homes as the seasons changed.”

They traveled on until the air began to smell wet and cool.

Ahead lay a pond, hidden in a bowl of reeds. Dragonflies darted over the water, their wings flashing copper, blue, and gold. A family of little horned dinosaurs drank at the edge.

“Hello,” called Sora.

The horned dinosaurs lifted their heads.

“Be careful on the west side,” said their grandmother, a stout dinosaur named Tenzin. “The ground looks dry, but it is soft beneath.”

“Thank you,” said Amaru.

Niko, who had been looking at the west side because it seemed like the fastest route, sighed.

They went around the east side instead. The ground there was firm, though it took longer. Halfway across, they heard a squelching sound.

Niko froze.

One of his back feet had sunk into a patch of mud.

“It is only a little stuck,” he announced.

Then his other back foot sank too.

“It is a little more stuck.”

Amaru did not pull him quickly. Sora did not panic. Marisol did not laugh, though she had to press her lips together very hard.

“Spread your weight,” Amaru said calmly. “Lean your chest forward. Slowly.”

Niko did as he was told. Amaru pressed broad branches beneath Niko’s feet while Sora gathered reeds to make a mat. Together they pushed, shifted, rested, and pushed again.

At last, with a great slurp, Niko came free.

His feet were coated in brown mud up to his knees.

Marisol looked at him. “You have two new boots.”

Niko gave a serious nod. “They are adventure boots.”

That evening, they reached a rise of land shaped like the curled tail of a giant creature. From there, they could see the green patch near the mountains.

But between them and it lay the widest old river channel of all.

It was dry at the center, but clouds had gathered over the peaks. Gray clouds. Heavy clouds.

Amaru looked at the sky. “We should not cross tonight.”

They made camp on the high rise. Sora tucked the seeds safely beneath a flat stone. Amaru built a shelter from fallen branches. Niko and Marisol gathered dry grasses.

Just as the stars began to peek out, rain started to fall.

At first it was a soft patter.

Then it became a drumming sound.

Water slid down the old banks. Tiny streams joined one another. The dry channel below began to shine, then ripple, then flow.

Niko stared wide-eyed at the water rushing through the path where they had hoped to walk.

“The river remembers,” whispered Marisol.

“It does,” said Sora.

All through the night, they listened to the water. It gurgled, splashed, and hurried beneath the rain. The old riverbed filled its curves again, not with a giant river, but with enough water to show everyone where it wished to travel.

In the morning, the rain had stopped. Mist hung low over the valley.

The channel below was still full, but not wild. It moved steadily around bends and through pools.

Amaru watched the water carefully. “We will wait.”

“But the new home is right there,” said Niko.

“And it will still be there after the water has had its say,” Amaru replied.

So they waited one day.

During that day, Marisol noticed how the water flowed around certain mounds instead of over them. She saw that some banks crumbled while others, held by roots, stayed strong. She noticed that birds nested high in the willow branches and that turtles rested on old logs well above the water line.

That night, when the water had shrunk back into a silver ribbon, Marisol said, “If we build our home near the spring, we should not flatten the little channels.”

Sora looked at her curiously. “Why not?”

“Because they belong to the water when it returns. And maybe small creatures need them too. We can build beside them. We can make paths over them with stones.”

Niko added, “And we can put the nest on a root-held hill, not on soft mud.”

Amaru’s eyes shone. “That is a wise plan.”

The next morning, they crossed where the water was shallowest, stepping from stone to stone. The cold water curled around their toes, but the current was gentle now.

At last, they reached the green patch near the mountains.

It was even lovelier than Sora had hoped.

A spring bubbled from beneath a rocky shelf. Ferns unfurled their curled heads in the shade. Young trees swayed in the breeze. There was room for a family to sleep, eat, play, and grow.

But there were also signs of the ancient river everywhere.

A narrow channel looped through the grass. A low mound of sand held burrows for beetles and tiny lizards. A hollow tree root made a home for a sleepy family of ground birds. A line of stones marked where rainwater would travel down from the hills.

“We cannot build over all this,” said Sora softly.

“No,” said Amaru. “A home should make room for those already at home.”

So the family chose a sturdy rise between two young trees. It was high enough to stay dry, close enough to the spring, and far from the water’s old path.

They built slowly.

Amaru placed the biggest stones in a circle, leaving gaps where rain could drain away. Sora wove reeds through branches, making walls that let cool air pass through. Niko carried fallen bark for a roof. Marisol laid smooth flat stones across the narrow channel, creating a little crossing path.

They did not cut down the hollow tree root. Instead, they built their nest around it, leaving a quiet doorway for the ground birds.

They did not fill in the beetle burrows. Instead, Niko made a small fence of twigs around them so no one would step there by accident.

They did not block the rainwater’s path. Along its edges, Sora planted seeds from the old umbrella trees.

“When these grow,” she said, “their roots will hold the soil, and their leaves will give shade.”

For many days, the dinosaur family worked. Other creatures came to see.

The river-mice arrived through a tunnel in the nearby bank.

Tenzin and her horned dinosaur family brought armfuls of soft moss.

The ground birds sang while the family worked.

Even a slow old turtle came from the spring and inspected the stone crossing.

“It is very good,” he said after a long pause. “It leaves room for water. This is important.”

At last, their new home was finished.

It had a warm nest beneath the stars, a roof that rustled pleasantly in the wind, a view of the mountains, and a little stone path that curved over the channel without stopping it.

That evening, the whole family rested together.

The sun slid behind the blue mountains. The ancient river landscape turned soft and purple. Far below, the old bends curled through the valley like the lines in a giant sleeping palm.

Niko looked at their new home. “It does not look like our old one.”

“No,” said Amaru.

“Will we miss the umbrella trees?” asked Marisol.

“We may miss them,” said Sora. “And we may visit them. But missing something does not mean we made the wrong choice.”

Marisol listened to the spring bubbling nearby.

“Our old home is still there,” she said. “And this home is here. We did not erase anything.”

Amaru lowered his great head beside the nest. “That is how the best journeys end. Not by wiping away where we have been, but by carrying its lessons with us.”

The family curled together beneath their new roof.

Outside, water whispered through its little channel.

The birds settled in their root-hollow.

The beetles tucked themselves into their sandy homes.

And in the dark, gentle valley, the ancient river rested beneath the earth, knowing that when it remembered how to flow again, there would still be room for it.