Pentagon inspectors are not amused that one Army database says Utah's vast Dugway Proving Ground has 1,192 square miles of test and training ranges within its Rhode Island-size borders, while a different database says it has only 456.

That is a difference of 736 square miles of maybe-it-exists, maybe-it-doesn't range land — about 11 times as big as Washington, D.C.

The Army Audit Agency found similar big differences at many ranges nationally.

The Deseret Morning News obtained the report through a Freedom of Information Act request.

In response to the request, Dugway officials incidentally said for the first time why they are seeking to expand the base's boundaries. They want to stop people, such as UFO-watchers who think Dugway is the "new Area 51," from spying on official activities from nearby mountains. The Army previously had refused to comment officially on its reasons.

Inspectors wrote in the new report that nationally, they found a 5.8 million-acre discrepancy — or 9,062 square miles — between two Army databases that sought to track how much range land the Army has.

Dugway Proving Ground had the fourth largest discrepancy among the national bases assessed, and had 8 percent of the total by itself. (Army-used ranges that had bigger differences included: White Sands Missile Range, N.M., 3.3 million acres; San Juan National Forest, Colo., 634,562 acres; and Fort Greely, Alaska, 631,556 acres.)

In a written response to the Morning News, Dugway officials said most of the reason for differences stems from the two databases examining somewhat different things.

It said that one, called the Range Property Inventory (RPI), looks at "current active and usable ranges on the installation." It had the smaller number at 456 square miles.

The other, called the Army Range Inventory Database (ARID), was developed by a contractor nationally as part of a process "to document all areas that had the potential of munition contamination any time during the history of the installation." It listed the larger number for Dugway at 1,192 square miles.

Dugway's response to the ARID calculation said, "Many times the same area is counted many times as it was used for different types of tests. There were also some differences between the two databases in determining what was buffer zone and what was range."

Dugway is where the military historically tested many of its defenses against chemical, biological and radiological warfare, as well as many of its new weapon systems. It has also been used for troop training and maneuvers.

The Army Audit Agency said that such differences in definition accounted for discrepancies at many of the other ranges, too. Also, it said the ARID database included some lands not owned by the military that were available for test and training under various agreements, and ARID sometimes had better acreage counts because it used satellite geographical information the other database did not have.