It's December. Rain falls on a small stream low on the mountain's northeast slope. Several drops hit the arching blades of grass shading a shallow pool at the edge of the stream. One hangs at the tip, lingers for a moment then pulls itself into a droplet we'll call "Hydroid."
The water below Hydroid is shallow, only 12 inches deep. But it is cool and clear, even in the pools where the water is still. It's easy for Hydroid to see the gravel bottom. Some of the rocks are arranged in a circle, about two feet in diameter. Below the rocks are small red, round pebbles about the size of peas. Hydroid counts 5,000 of them when it sees that some pebbles have eyes! These are eggs. Each eyed egg is a fertile egg. And each fertile egg has a chance of becoming a salmon. Hydroid landed right over a fish nest. Fish nests are called redds. Hydroid knows the salmon in this small stream are all chinook.
The tiny fish are a little more than one inch long. They are called alevins. Each has an orange pouch on its belly. The pouch is a yolk sac that provides food during the first few weeks of the salmon's life. The alevins hide deep in the gravel. One night in March, the young fish slip up through the gravel. The yolk sacs are gone. The young fish, now called fry, are hungry and ready to eat, but do not stray far from the clump of grass where Hydroid is perched.