La Frontera: THE UNITED STATES BORDER WITH MEXICO by Alan Weisman; photographs by Jay Dusard (Harcourt Brace Jovanovich: $29.95; 224 pp.)

The publishers of “La Frontera” apparently could not decide if they wanted the book to be a serious and thorough study of the U.S.-Mexico border, or a coffeetable book about the often picturesque borderlands and colorful North Americans and Mexicans who live there. That is unfortunate, because in either case, the book would have been a useful contribution to the growing body of literature about the nation’s southern border. Instead, it falls short on both counts.

While author Alan Weisman’s musings about life along the border are often interesting and well written, they are far from profound and offer no solutions to the many complex issues (illegal immigration, drug smuggling and environmental pollution are only the most obvious) that have increased the political tensions between Mexico and the United States in recent years. In fairness to Weisman, a free-lance writer who teaches border studies at Arizona’s Prescott College, the format of the book limited any chance he had to write long or complex essays about the challenges facing the borderlands.

Still, the black-and-white photographs by Jay Dusard, a photography teacher in Prescott, are magnificent. His landscapes in particular are reminiscent (at least to my unpracticed eye) of the classic photographs taken by Ansel Adams. But if this is a coffeetable book, why aren’t there more of Dusard’s pictures? Only 56 photographic plates are scattered throughout the 200-odd pages of large-type text, and not all the people and places Dusard and Weisman visited during a year of traveling the length of the border--from Brownsville, Tex., and Matamoros, Tamaulipas, on the Gulf of Mexico, to the Pacific beaches between San Diego and Tijuana--are illustrated. This only heightens the frustration of a reader who, realizing he will not learn anything new about the borderlands, wishes he could at least see more of the people and places Weisman and Dusard visited on their enviable journey.

And despite Weisman’s obvious empathy for the people of the borderlands, he is at times less careful in writing about them than he could be. His profile of a Mexican drug kingpin in Ojinaga, Chihuahua, for example, is troubling enough because of its almost-admiring tone, but Weisman apparently made no effort to verify the man’s boasts of drug murders and underworld conquests with any reputable law enforcement agency. And in writing about ethnic tensions between Mexican-Americans and Anglos in Texas’ Rio Grande Valley, he’s downright sloppy. At one point, he lumps three distinctly different Chicano groups--Cesar Chavez’s United Farm Workers Union, Los Angeles’ old Brown Berets and Texas’ La Raza Unida party--into one organization. And he oversimplifies the important community-organizing effort under way in South Texas under the auspices of the Roman Catholic Church and the Industrial Areas Foundation, which was founded by the late radical organizer Saul Alinsky. That same approach has been remarkably successful in major cities like Los Angeles, Houston and San Antonio, but you’d never know it from Weisman’s description.

Despite such shortcomings, “La Frontera” is worthwhile. Weisman loves the borderlands and wants other people, mainly his fellow North Americans, to better understand and appreciate them. That is why the readers who will benefit most from his book are those who know almost nothing about the borderlands. Weisman provides a good overview of the region’s history and problems--a past and issues that are as misunderstood in Mexico City as they are in Washington, D.C. “La Frontera” will give readers in such far-flung places a better sense of a unique region that Weisman and others consider a “third country” between Mexico and the United States.