The Missouri River and its components, the tributaries and reservoirs, must get awfully tired of being studied.

The former Big Muddy should brace itself, because a group representing states and tribes wants the Army Corps of Engineers to analyze the river system - again.

The idea is to discover whether the corps is maintaining the right balance among the interests of all who share use of the river.

If it were only as simple as reinventing the wheel. The corps goes to great length - and expense - to produce an annual operating plan for the Missouri River Mainstem System. It's gospel for those who decide the water elevation in reservoirs, when there will be pulses and so forth. But it's Congress that has given the corps its general orders about flood control, barge navigation, recreational use, drinking water supply, on and on.

It will take Congress to redefine the priorities, especially if people upstream from Sioux City, Iowa, are to be satisfied. The navigation business on the lower river no longer is vital, but the managers of the river have to take it into account in determining the amount of water in the channel during a few months.

A group called Missouri River Association of States and Tribes wants the corps to study its own management policy. The group, including two appointees by the North Dakota governor, in February voted to ask the corps for a "Section 216 Study" under the federal flood control act. In essence, the corps would study its own policy stated in the operating plan. The plan comes from data and public comment - study. So the 216 would be a study of a study.

It should be noted that the group, MoRAST, represents tribes and states, but there's representation conspicuously missing: the state of Missouri. That's where much of the remaining barge traffic is located. Missouri has exerted strong political pressure to keep its stretch of the river navigable. The upstream states would like to see a study built on an assumption that navigation would cease to count. That's fine. Recreation creates many times more wealth in the more northerly states than barge traffic does down lower.

The Missouri River and its tributaries all the way into Montana and Wyoming are a treasure to hunters, anglers and other people who love the outdoor life.

But it's problematic to order a study whose outcome is prescribed. Why not just stick with the corps' operating plan until Congress acts to change its assumptions?

And feature this: The Army Corps of Engineers doesn't know offhand how much a Section 216 study of the massive Missouri River system might cost. The corps' expectation is that states would pick up half the cost.

The corps agreed in June 2003 to do a Section 216 study of a single dam and its reservoir lapping into Virginia and North Carolina. It was to cost $3 million. The corps would pay half, the states splitting the rest. That was for looking at one piece of water. There are six reservoirs in the Missouri River system and several thousand miles of channel in the main river and its branches.

It seems better to beseech Congress for needed change than to spend who knows how many millions of dollars on a document, when Congress would have to act anyway.