This is a work in progress, not sure when or how long it will take to finish it, but I think it has a good start so far. I am not sure which horse is going to be the main character yet, and I am thinking that maybe it will end up being a series of books, if each of the characters wants their own story to be told.
Glacier Bay Cove Farm and Stables lays between two parallel mountain ranges, leading from the ocean up to a large mountain valley hidden among the tall mountain peaks.

Mystic King tossed his head as he trotted up the mountainside to the lookout point, as Sir Snowcap soared in lazy circles overhead. When he reached the lookout point, Mystic King stepped to the edge and looked out over the valley stretched out below him. He lifted his head and took a deep breath of the fresh, clean mountain air.

“Let's go see what Grumbles is doing,” Chinook Whisky said, and Solar Flash and Silver Obsidian nodded in agreement. “I don't think it's a good idea since he just came out of hibernation,” Moonlight Star said. “Whatever,” Chinook Whisky snorted as he turned to trot away, followed by Solar Flash and Silver Obsidian. The other foals glanced back and forth between Moonlight Star, and Chinook Whisky, Solar Flash and Silver Obsidian, who were disappearing over the hill. Moonlight Star sighed, before glancing at Star Silver. “Let the adults know what's happening,” she said and Star Silver nodded before galloping away.

Grumbles was wading into the stream, for some fish, when Chinook Whisky, Solar Flash and Silver Obsidian trotted up. He looked up when Chinook Whisky stepped down into the water and began pawing at it, scaring the fish away. “ What are you doing,” Grumbles growled, and Chinook Whisky reared, before continuing to paw at the water.

Moonlight Star tossed her head, but stood her ground, as Grumbles stood on his hind legs and rumbled in anger. Behind her, Silver Obsidian quivered in fear, as he showed the whites of his eyes. Autumn Blossom stepped out of the woods and walked forward, to stand beside Moonlight Star. Sir Snowcap folded his wings and spiralled downwards to land on a large rock. He glanced at Autumn Blossom and the two foals, before looking at Grumbles. He spread his wings and launched from the rock, gliding towards the stream. Upon spotting a fish, Sir Snowcap extended his talons and he snatched the fish from the water, before turning and gliding back to drop the fish in front of Grumbles. He glanced up at Sir Snowcap, and nodded before dropping to all four legs and beginning to eat the fish. Autumn Breeze nudged Moonlight Star, before turning and nudging Silver Obsidian. She very gently nudged the two foals, before guiding them back into the forest.

Rain Dancer and Misty Queen galloped up to Autumn Breeze, Moonlight Star, and Silver Obsidian. They checked the two foals for any injuries, before turning to Autumn Breeze and thanking her for escorting the foals home safely. Autumn Breeze dipped her head, before turning and making her way back into the woods.