"There are many members of Congress who are ... deeply concerned about the proliferation of off-reservation Indian gambling casinos," said Rep. David Wu, D-Ore.

Wu, who opposes the gorge plan and off-reservation tribal casinos in general, said the federal decision "will give Oregonians a chance to reconsider the kind of state we wish to be."

On Friday, the Interior Department temporarily blocked a proposal by the Confederated Tribes of Warm Springs to build a casino in Cascade Locks, about 40 miles east of Portland in the scenic Columbia River Gorge. Tribal leaders estimate the casino would draw 3 million people a year.

The Interior Department left open the possibility that it will approve the deal later, but said it would not approve the casino unless it first rules that the off-reservation land can be taken into trust for gambling -- a process that could take years.

Rep. Greg Walden, R-Ore., called the decision "a bit of a last-minute surprise," but noted that the agency did not reject a compact signed with Oregon Gov. Ted Kulongoski. Instead, officials merely required the tribes to acquire the land before the department will consider the merits of the state deal.

"Frankly, this procedural change seems to track more closely with the requirement of federal Indian gaming law," said Walden, a casino supporter whose district includes the proposed casino site.

The Warm Springs will need to complete an environmental impact statement to take the lands into trust, so the public will have ample opportunity to comment before any final decision is made, Walden added.

Meanwhile, a key House Republican who wants to restrict off-reservation gambling called the decision proper.

"The Interior Department's decision didn't address the merits of the compact, but rather the procedural grounds related to approving a compact before placing lands into trust," said House Resources Committee Chairman Richard Pombo, R-Calif.

"Nonetheless, concerns about off-reservation gaming continue to be a topic of discussion in local communities, state governments, and among members of Congress. So we are all committed to finding practical solutions to the concerns raised by many around the country," Pombo said.

Pombo has proposed creation of "Indian Economic Opportunity Zones" where numerous tribes could build casinos in one area, as a way to block proliferation of off-reservation casinos.

Most of the nation's 411 tribal casinos are on reservations, but as Indian gambling spreads, tribes are increasingly looking beyond their borders for better locations -- including urban areas such as Denver and San Francisco Bay.

Indian gambling pulled in around $18.5 billion in 2004, nearly double the take from gambling at major Nevada resorts.

The head of an Indian gambling group said the Interior Department decision, contained in a letter by Associate Deputy Secretary James Cason, was not surprising.

"It's about government process. They're saying the land-trust process has to go forward before the other process (of federal approval) can proceed," said Mark Van Norman, executive director of the National Indian Gaming Association, which represent 184 tribes across the country. The group has not taken a position on Pombo's proposal, which has not been formally submitted as a bill.

Cheryl Schmit, head of Stand Up for California, an advocacy group that has fought some Indian gambling proposals, called the Interior decision "outstanding."

The decision means that Interior and the Bureau of Indian Affairs "are going to adhere to the process," Schmit said. "They are not going to skip a step in the process just because they've got a governor's compact."