PORTLAND, Ore. -

A top official in the Oregon state treasurer's office says a bridge to Washington over the Columbia River could be viable if several stringent conditions are met.

In a memo to State Treasurer Ted Wheeler obtained by The Oregonian, Laura Lockwood-McCall says the U.S. Coast Guard must grant a bridge permit by Sept. 30.  Next, the Oregon Department of Justice must find it legal for the state to construct parts of the project in Washington.

Finally, the two states must enter construction and tolling agreements giving Oregon exclusive control over toll rates.

Washington's Senate failed in June to contribute matching funds for the bridge.

Even if those conditions are met, money money must be found to cover annual light-rail operating costs for the extension to Vancouver.

Then Congress must award an $850 million light-rail grant early next year. And the Federal Highway Administration has to give a $900 million loan to Oregon by next summer.