Miller takes a careful look at a temporary water system--a vernal lake in Alaska whose emergence and disappearance each year has given rise to a unique ecosystem. Spring's melting snows collect in a low-lying area to form a lake, which becomes the habitat of moose, bald eagles, golden ducks, and beavers. The lake drains and evaporates slowly; ducks and beaver move on to a bigger lake, while new animals move in, browsing on the soggy lake bottom, which eventually dries out and becomes a meadow. Sparrows, voles, and shrews appear, along with the moose who sleep in the long grass. In autumn the birds are on wing for warmer locales; in winter the field is covered with snow, and the cycle will soon repeat itself. Van Zyle's realistic paintings capture the details of Alaska: moose fur, jangling golden aspen leaves, and the faint rainbows of northern lights in the night sky. An annotated glossary and an author's note fill out the text, which--despite the inclusion of the many creatures that are born or visit the habitat--is more of a poetic chronicle of the lake's life cycle than a factual one. Most readers will be fascinated by the existence of such systems, and only sorry that the ""diving beetles, caddisflies, and water boatmen"" Miller mentions in her note are not featured elsewhere in the book in more detail.