CASCADE LOCKS, Ore. - For 12,000 years or more, Columbia River tribes gathered along the banks near here to do business with distant tribes. Now they want to come back - not to cut deals in fish and baskets, as their ancestors did, but to deal blackjack and poker. The Confederated Tribes of Warm Springs want to close a small casino on their reservation in remote central Oregon and build one on nontribal land in this town on the banks of the Columbia, much closer to Portland, the state's largest city, and the thousands of gamblers a casino would attract....