ARIZONA (By Jon Kamman, Arizona Republic) JunE 29, 2005 - Leaders of two Arizona Indian tribes and two from other states were put on the spot Tuesday by a U.S. senator who asked relentlessly why they don't disclose the amount of their casinos' revenue.

None of their answers appeared to satisfy Sen. Tom Coburn, R-Okla., as the Senate Indian Affairs Committee explored whether 17-year-old federal regulations governing tribal gaming need updating.

Coburn's questioning came as Vivian Juan-Saunders, chairwoman of the Tohono O'odham Nation, and Dallas Massey Sr., chairman of the White Mountain Apache Tribe, testified at a Washington, D.C., hearing that Arizona's regulation of reservation gaming could serve as a model for the nation.

Committee Chairman Sen. John McCain, R-Ariz., said one reason for a current series of hearings on Indian gaming is to ensure that patrons of the casinos, nearly all non-Indians, are protected by "honest, straightforward and transparent" operations.

Indian gaming has mushroomed into an industry with annual revenue estimated at more than $18 billion since Congress set ground rules in the 1988 Indian Gaming Regulatory Act for the roles of tribes, states and the federal government.

The hearings come as tribes, especially those on reservations far from urban centers, increasingly seek to open casinos on trust land or properties they buy closer to cities.

Also, tribes with lucrative gambling interests have been prey for what McCain characterized as unscrupulous consultants and lobbyists.

Coburn asked at least eight times for an explanation of tribes' non-disclosure policies. He said all U.S. businesses and governmental entities are required to report revenue at least privately to the Internal Revenue Service, and tribes would not jeopardize their sovereignty if they voluntarily opened their books.

Joseph A. Pakootas, chairman of the Colville Confederated Tribe in north-central Washington state, said, "We're not public companies; we're actually like different countries."

Juan-Saunders said mistakenly that the National Indian Gaming Commission, a federal agency, prohibits disclosure.

Massey noted that in Arizona, a single figure representing all tribes' gambling revenue is reported to the state. But Coburn pressed on, saying, "I want it on the record" why tribes don't report individually.

The senator took issue with a response by Deron Marquez, chairman of the San Manuel Band of Mission Indians, who run a casino some 30 miles east of Los Angeles.

"The main reason (for non-disclosure) is trust," Marquez said. "Every time we have shared information with the 'outside world' . . . it's always been something that has come back to hurt us."

Coburn retorted that tribes are not harmed by accounting for their number of Indian Health Service patients, and the figures allow Congress to attend to tribal health care needs.

Revealing gaming revenues "in the long run would build trust and support for Native Americans," he said.

Marquez said the figures are not withheld from tribal members, and his council is moving gradually toward possible wider disclosure.