Imagine spending two days lost on Casper Mountain. Now imagine being blind, and spending two days lost on Casper Mountain.

Local author Gayle Irwin asked the children in her audience at the Natrona County Public Library to close their eyes and think about what that would be like. Irwin's springer spaniel, Sage, is blind. She also spent two days lost on Casper Mountain, after losing her way chasing squirrels.

Irwin read to the children from her self-published book, "Sage's Big Adventure: Living with Blindness," on Saturday at the Natrona County Public Library. Irwin's inspiration for the book came from Sage and how the dog has adapted to life without sight.

Irwin and her husband adopted Sage from a Montana Humane Society shelter. At the time, nobody mentioned that it seemed Sage was going blind.

"Whether they knew or not, I don't know," Irwin said.

Sage, who is eight years old, has progressive retinal degeneration, a genetic disease, and Irwin said her companion's blindness might be the result of in-breeding.

Irwin explained to the children that Sage uses all her other senses to learn where things like couches and chairs are. Irwin said Sage learned to avoid bumping into couches and chairs because she could feel a difference when she stepped onto the throw rugs beneath Irwin's furniture.

"Now that's pretty smart, don't you think?" Irwin asked.

Dogs also have an especially keen sense of smell.

Irwin and her husband also taught Sage to step up or down, so that when they take her for walks, she won't stumble over sidewalk curbs.

The children at Irwin's reading eagerly petted and played with Sage when she arrived at the library.

Sisters Ashton and Payton Hallsted both want to be veterinarians when they grow up.

"We're dog lovers," Ashton, 10, said.

The girls have two dogs at home, a beagle named Lucy and a chocolate lab named Bella.

"We like to wrestle with them," Payton, 7, said. "It's hard to get Bella down."

Irwin said she hopes Sage's courageous spirit will help inspire the children she meets.

"I was very inspired by how she adapted," Irwin said. "Children are going through a lot nowadays."

Reach Jasa Santos at (307) 266-0593 or at Jasa.Santos@trib.com.