What is the role of a national park? How should we value what lies within the boundaries of a national park? Those are simple and yet provocative questions these days. Some answers -- perhaps the answer -- can be found in a new book that chronicles Yellowstone National Park's bittersweet history with the snowmobile.

The history is bittersweet because snowmobiles both make Yellowstone so much more accessible in winter for many, and yet for many they cheapen the park. They open up the park's wonders to folks who would never otherwise venture into the world's first national park during the winter (and perhaps not even during the summer). But they also degrade its natural resources and run contrary to the essence of what a "national park" should be, what it should reflect.

“In a park we are concerned with the effect of snowmobiles on the spirit of wilderness, on the spirit of the out-of-doors. These mechanical intrusions create a diluted, lukewarm ‘concensus’ (sic) environment. The whole park idea is cheapened.”

So noted Adolph Murie, the renowned conservationist who called Jackson Hole, Wyoming, home, back in 1967 when the fledgling snowmobile community was starting to cast eyes upon Yellowstone. His comments give readers something to mull as they launch into chapter two of Yellowstone and the Snowmobile: Locking Horns Over National Park Use, which chronicles the history of the park and the snowmobile.

The book is unique for at least two reasons:

* It tracks the history of the snowmobile in Yellowstone, reaching back to 1949 when the first "snowplanes" entered the park for tourism purposes, and proceeding right on up to last fall's dueling judicial rulings over the fate of snowmobiles in the park.

* Two, it was written by a Yellowstone park ranger.

Michael J. Yochim, who has spent the past 20 years in Yellowstone in various roles, tackles this task from an impartial, analytical position. Indeed, he obviously cast his net far and wide for the background that propels the book, as evidenced by the more than 80 pages of footnotes that fill the bibliography.

It's a heft bibliography because Mr. Yochim needed to cover so many bases: There's the natural setting, the political intrigue, and the confrontational tenure that has developed -- enveloped might be a better word -- about this topic and this park as conservationists paired off against not just the snowmobile industry but those who believe they have a right to recreate as they see fit in national parks.

While the book focuses on over-snow travel in Yellowstone, it broadens at times to create images of what the park can be like in winter. In touching on some of the early history of winter in Yellowstone the author recounts the need for District Park Ranger Frank Anderson in 1933 to obtain an official Weather Bureau thermometer that could measure temperatures below 65 degrees below zero Fahrenheit, as his bottomed out at that mark on February 9 at the old Riverside Ranger Station on the Madison River.

In building towards the snowmobile's arrival in the park, Mr. Yochim commits considerable space to the debate surrounding plowing park roads in winter. Ironically, in light of recent events, that debate was driven largely by Cody, Wyoming, and the state of Wyoming. It's rich background that shows the early role politics played in managing our national parks, and which helps one understand the current concerns of Cody.

Indeed, judging from this section an entire book could be written on the "outside-looking-in" feelings of some Codyites.

From time to time Mr. Yochim drops in, perhaps to emphasize a point or perhaps only to help unravel the decades-long debate over snowmobiling in the park, thoughts, such as Mr. Murie's above, that question the propriety of snowmobiles in not just a national park setting in general, but in Yellowstone National Park specifically. Another example of that device appears on the doorstep of chapter three:

We are once again at a critical crossroads and are teetering on the brink -- we have the opportunity to help preserve uniqueness or to proliferate a watered down, carbon copy mediocrity we can find elsewhere -- Yellowstone Park Ranger Gerald E. Mernin, 1984

Attempting to Band-aid winter requirements at Yellowstone is an invitation to potential tragedy. -- NPS Regional Director Lorraine Mintzmyer, 1987

What's particularly refreshing, in light of the author's employer at the time he researched and wrote this book, is that he doesn't pull punches when he addresses the Park Service's role in the present-day mess that has resulted in lawsuits, not park managers, deciding what's best for Yellowstone.

Inconsistent winter visitation policies characterize much of the park's history; some might say that winter use happened to Yellowstone, rather than Yellowstone managers planning and controlling it in any organized manner, at least in the early decades. (emphasis in original)

Mr. Yochim builds on that in his conclusion by comparing Yellowstone, at least when it comes to winter use, to the Wonderland that Alice fell into.

Alice might feel at home in the Yellowstone Wonderland, for the park is fascinating, strange, and unpredictable, and things are sometimes not as they would seem -- especially when it comes to elements of the winter use debate. For instance, conservationists fighting the good fight for snowcoaches in Yellowstone now find themselves perversely advocating for the most energy-intensive transportation mode of them all. With the best of intentions, they have remained consistent in their support for these vehicles so long that it seems they have lost sight of their larger goal: instituting an environmentally benign and affordable mode of transportation in Yellowstone.

Alice might feel comfortable in a park manager's shoes as well, at least in one way. She would no doubt find a familiar sense of irony in the plowing debate. Plowing would be easier for park managers than their current program of nightly road grooming, but public opinion -- so in favor of plowing forty years ago -- seems set against it now, even though plowing is common outside the park. Still, many park managers would welcome plows in exchange for grooming machines; many expect that climate change will soon negotiate that exchange regardless of popular opinion. Though they are concerned about the impacts of global warming on the park they should protect, managers may privately and perversely find themselves hoping that it happens quickly, rendering the whole winter issue moot and negating the need for grooming machines.

Yellowstone and the Snowmobile is a great addition to your library, both for the context it provides and as a ready reference that uncovers the many, many fingerprints that have been left on this contentious issue. An issue, by the way, that has not yet seen its final chapter.