Splendid short riverside rustications in a first collection from Moore (Philosophy/ Oregon State Univ.). These are ``river essays because I began to write each one alongside a stream or floating down a river, and so they may still carry the smell of willows and rainbow trout,'' explains Moore. Indeed they do, all 20 of these little river songs (the author might call them essays, but that's too dry a word). For each of the waterways she visits, Moore provides a bite of history (both geologic and social) and an appreciation of its creatures and its flowerage; she discloses just why she and her family happened to be on the water and what they did there. Each river gives her pause for reflection, conjures something from her imagination, an idea that she then turns and fashions in an admirably fresh, agile way. While noodling about on the banks of the Little Stoney River, she has her eye out for ticks, but her mind is busy trying to unravel the knotty notion of time: ``Einstein was right: time can't be a constant. Its speed depends on where you are and the people you are with.'' Or while heading to the John Day River, enjoying the colorfully striped volcanic landscape and musing on the sorry fate of the river's pioneer namesake, she can't help but ponder the natural equilibrium of joy and pain: ``Maybe our joy is the cosmic complement of a doomed rhinoceros stampeding away from a suffocating sea-blue cloud of ash.'' A visit to the Smohalla River occasions a thought or two on housekeeping in the wild: ``Domesticity is the central pleasure of the wilderness experience,'' and she goes on to explain nimbly and whimsically exactly why such is the case. Moore's collection sparkles as much as one of her sun-dappled streams.