We've all heard a lot recently about the long-running dispute over plans for a new bridge across the St. Croix River, one of the national's original Wild and Scenic Rivers.

It's time to face the facts. The current proposal, for a nearly $700 million freeway-style bridge that violates federal law, is no longer affordable to either Minnesota or Wisconsin.

Current cost estimates for the project -- a mammoth proposal that would span nearly a mile and rise more than 150 feet above the river -- exceed $640 million and could easily swell to $700 million, with Minnesota's share at least $320 million.

Meanwhile, we face a state budget deficit of $5 billion. The Minnesota Department of Transportation projects a $270 million annual repair and maintenance shortfall in coming years -- and a projected shortfall of $50 billion over the next two decades.

According to MnDOT estimates, this massive highway expansion project will serve 9,000 daily round trips (18,000 crossings). As few as 20 percent of these are Minnesota drivers, based on an informal survey.

By contrast, the Wakota Bridge along Interstate 494, which cost $300 million (including related projects), has 90,000 vehicle crossings each day.

How can we tolerate this subsidy for new suburban sprawl in western Wisconsin, just six miles north of the existing, underutilized I-94 bridge, at a time when proposed Minnesota funding cuts could result in large fare hikes and deprive thousands of transit service?

Why should Minnesota taxpayers foot the bill for unsustainable development in western Wisconsin at a time when local property taxes throughout the Twin Cities metro area are rising, in many cases by double digits?

A reasonable, modestly scaled St. Croix bridge design could free up hundreds of millions of dollars for genuine priority projects such as fracture-critical replacement bridges elsewhere that MnDOT engineers rate at decisively higher urgency than the Stillwater Lift Bridge.

At this very moment, two new Mississippi River bridges are being built at comparable sites at much lower cost than the proposed St. Croix superbridge -- the Lafayette Bridge, at a cost of $185 million, and the Hastings Bridge, at $120 million.

Let us be clear: We strongly support a new river crossing to replace the Stillwater Lift Bridge.

Indeed, more than 25 local and regional environmental groups and the Minnesota Environmental Partnership have publicly supported a new bridge that would bypass downtown Stillwater's traffic backups and preserve the unique character and scenic qualities of the Lower St. Croix National Scenic Riverway.

There is strong precedent for creative and transformational leadership to resolve similar problems.

Twenty-five years ago, the Minnesota and Wisconsin transportation departments proposed a large interstate-style bridge at Prescott.

Rather than ram through a proposal that would irreparably harm the Lower St. Croix, Gov. Rudy Perpich instructed MnDOT to devise a low, slow solution that preserved the priceless character and quality of the river at that location, and it was done.

There is no need to poke a huge hole in the National Wild and Scenic Rivers Act, one of the most revered legacies of U.S. Sens. Gaylord Nelson of Wisconsin and Walter Mondale of Minnesota -- an act that has benefited millions of Minnesotans over four decades by preserving an incredible natural, recreational resource literally on the doorstep of the Twin Cities.

A balanced, affordable design at a scale that respects and protects the National Riverway is not just right for the environment -- it is the fiscally responsible course as well. Let us not surrender to the false choice advocated by supporters of the $700 million superbridge.

One month ago, Gov. Mark Dayton indicated that all options were on the table for a new St. Croix crossing. We urge him to oppose efforts to undermine the Wild and Scenic Rivers Act and instead work with the experts and leaders in his administration to identify a sensible, balanced solution.

We stand ready and eager to support a new river crossing that is environmentally and fiscally responsible.

Luther Dale is chair of the Sierra Club North Star Chapter.