Excerpt:

The landscape was peppered with boulders and small snowfields, several of which spread across the trail. Scatter snorted and picked his feet up high, clearly skeptical. Jay preferred hiking across snow than hiking across scree. He would have liked to throw it around, but he didn’t want to spook the horse. He took advantage of it, though, when they stopped at a runoff stream near one such glacier and Linda dismounted to crouch and refill her canteen. He hit her square in the back with a big, loose snowball.
She looked up in shock. Then she charged at him, picking up fistfuls of snow as she went. He retaliated wildly. They had a fantastic battle going for about thirty seconds. She shoved a fistful of snow down the back of his shirt before he could grab her arms and stop her. At that moment, her hat blew off and she had to chase it downhill a ways. As she put it back on her head, she stiffened.
“Sorry, Jay,” she muttered. “I’m a paid employee of the Forest Service, not some hoodlum. I can’t do stuff like that.”
He laughed tossed one more snowball at her, which she dodged.
“I’m serious,” she said. “I shouldn’t even be traveling with you, let alone having snowball fights.” Something inside Jay flip-flopped. He tried to keep his face cheerful looking.
“Okay, party pooper,” he said. “I’ll try to behave myself.”
“No, I’m serious,” she said, shaking her head. “I can’t go around befriending hikers. I have to be more professional than that.” Blushing deeply, she swung back up into the saddle and turned Scatter sharply down the trail. The horse was uneasy, and seemed glad to pick up the pace. Jay hurried to close his water bottle and get his pack back on. He couldn’t let her just leave.
“Linda, wait!” he called. She pulled Scatter up short with a certain amount of difficulty and looked over her shoulder, yelling him directions as a sort of afterthought.
“Just follow this trail to the intersection with Horton Pass. You can either take a right down to Mirror Lake or a left up the moun--” she froze mid-sentence.
“What?” Jay called, starting to walk down the trail after her. She regained her voice and screamed,
“LOOK OUT!”
Before Jay could turn around, he felt something huge crash into his backpack. A searing pain cut into his left shoulder, and he yelled. But all he heard when he opened his mouth was a feral scream! He did a quick 180, trying to shake his attacker off, and saw a huge black-tipped tail thrashing out of the corner of his eye. A cougar! As it thrashed, he tried to lean forward for balance, but it must have weighed a hundred pounds. He toppled over backwards and plummeted down the trail head first.