In that spirit, our preliminary conclusion is that this is a terrible idea.

The developers want to build a road across the lake from Provo or Orem to Pelican Point, on the lake's western shore. That point is just north of their Mosida Orchards project where 20,000 new residences are planned. The causeway would give the Mosidans a direct commuter route of four to six miles across the lake, and it would spur other development on the lake's largely uninhabited western shore.

The causeway might be an economic boon, assuming that Provo or some other government in Utah County could come up with $200 million or more to build it. (No one really knows for sure what it would cost.)

But, while we concede that this proposal has not been studied in any depth, we can think of two excellent reasons to sink it.

First, Utah County faces hundreds of millions of dollars of highway and mass transit needs, starting with the rebuilding of I-15, that must lay first claim on transportation construction funds. A causeway would have to be placed at the bottom on any priority list.

Second, if the checkered experience with causeways on the Great Salt Lake is any guide, this scheme for Utah Lake could be an environmental disaster for one of the largest bodies of fresh water in the state. The law of unintended consequences hangs heavy over this proposal.

When the Southern Pacific Railroad built the Lucin Cutoff across the northern arms of the Great Salt Lake a century ago, its engineers did not anticipate the challenges of the shallow lake's bottom, a soft ooze in which pilings 70 feet long simply disappeared.

When a long section of trestle was replaced in the 1950s by earthfill, it cut off the north arms of the lake from the south, concentrating brines in the north and affecting both brine shrimp and mineral extraction. The state is still wrestling with whether and how to undo this bit of mischief.

On Utah Lake, efforts to save the endangered June sucker, a native fish, have focused people's attention on how to reverse more than 150 years of environmental degradation. If the lake is to be reclaimed as something more than a carp-infested cesspool, Utahns must get serious now, because the lake is teetering on the brink of environmental collapse.

We don't know how a causeway would affect efforts to improve Utah Lake as a refuge for waterfowl, game and native fish and human recreation. But we do know the record of causeways on Utah's inland sea to the north, and it isn't encouraging.