In "The Black Rhinos of Namibia," environmental activist and prolific author Rick Bass travels to Namibia to spend time with conservation groups and learn about the endangered black rhino. Although he doesn't indicate a prior specific fascination with rhinos, Bass quickly becomes utterly enchanted by them.

"Rhinos" is loosely divided into three parts and an epilogue, and "Part I: Pastoral" doesn't actually contain any rhino sightings; instead, Bass sets the scene in his digressive way. Subjects range from "megafauna" (not only the rhino, but also the grizzly bear in his native Yaak Valley in Montana), to humans' and rhinos' place in the world, to an overview of South African politics and the different rhino conservation tactics over the years, including the hiring of former poachers to protect rhinos.

"Part II: Wild," the longest section, features Bass' experiences out tracking animals in the desert. In the comparatively short "Part III: Dust" and epilogue (which is almost as long as Part III), Bass' trip winds down at a couple of camps different from the one he stayed at in Part II -- much cushier ones, with a smattering of modern conveniences that he finds a bit jarring in such a severe landscape.

A thorough observer, Bass is in awe of the Namibian "basalt prairie" landscape, and expresses this awe freely and sincerely. Dreamer that he is, though, he is also a prodigious rambler. He employs an impressive quantity of em dashes, sentences can expand to near-paragraph length, and he seems to prefer three or four descriptors where one or two might suffice ("beguiling and elusive and non-knowable," "huge or powerful or dramatic," "in flavor and tenor, in intensity and tone," "pitching and yawing and rolling"). As his thoughts wander, there are a few themes that he returns to again and again, with the most heavily -- a little too heavily -- frequented one being that of intelligent design vs. evolution. Bass cannot fathom how a creature such as the rhino, so fantastical and seemingly perfectly fitted to its inhospitable environment, could have arisen from chance or trial-and-error evolution.

Given Bass' proclivity for discursive musing, it came as a pleasant surprise to discover in later parts of "Rhinos" that when he focuses on a specific experience, his writing can actually become downright page-turning. Detailed descriptions of close calls during some rhino trackings, and a couple on elephant sightings, are among the book's most absorbing and memorable passages.

I can't help but wonder what "Rhinos" could have been like with more such editorial focus. All the same, Bass provides a singularly thoughtful portrait of a unique animal, and a meditation on mankind's relationship to both it and the natural world as a whole.

Kim Hedges is an editor and book reviewer in the San Francisco Bay Area.