In Washington, D.C., conference rooms, the proposed pipeline running from Alberta, Canada, to Texas refineries on the Gulf of Mexico may look rather attractive. The 1,700-mile Keystone XL pipeline would supply the United States with abundant crude from a friendly neighbor. It would create 20,000 jobs, says owner TransCanada. And it would be reasonably safe for the environment, according to a U.S. State Department study.

From the Nebraska Sand Hills over which this pipeline would go, the views are considerably less supportive. This fragile landscape of tiny lakes and giant sand dunes sprouting grass could have come from another world. Nebraska Highway 2 is a two-lane voyage through its heavenly solitude, punctuated now and then by a small town. Some years ago, Car and Driver magazine called it one of the most scenic stretches in America.

I recall being stopped for speeding while flying along a magnificent piece of this empty road, somewhere in Grant County. The officer wrote us a ticket while wanting to know that our visit through his jurisdiction was otherwise pleasurable. The sand hills are like that — not just a unique environment, but part of a rural culture in which patrolmen have time to chat with speeders.

Am I a wee bit the hypocrite? Here I was burning fossil fuels on my vacation, and now I'm talking against a project to bring in more oil. There is a national security case for securing up to 700,000 gallons of oil a day from a part of the world that's not volatile, dangerous and perpetually angry at America. While I'm all for clean energy, we'll still need oil for some time.

But the Great Plains have some conflicting needs. Under the Nebraskan dunes and parts of Kansas, Wyoming, Colorado, Texas and New Mexico lies the shallow Ogallala aquifer, an underground sea of water already much depleted.

Suppose a pipeline spill poisoned this precious source of water for irrigation and drinking. (Nebraska Gov. Dave Heineman, a Republican, wants it moved to run along an existing pipeline in the eastern part of the state.)

We hear assurances from the State Department that any mishaps are controllable. But then you have the recent example in Michigan, where a pipeline rupture released 840,000 gallons of tar-sands crude. Some 35 miles of the Kalamazoo River remain closed a year later. Another pipeline transporting the same kind of crude suffered two leaks last spring in North Dakota and Kansas and had to be shut down.

The proposed Keystone XL would carry the same especially corrosive oil over shallow aquifers under sandy soil. And how much confidence can one place in the small agency that's supposed to regulate it?

Simply producing oil from tar sands releases far more greenhouse gases than from conventional crude. Some argue that Canada is determined to exploit the resource and will ship it to China if America doesn't take it — and on tankers that burn still more fossil fuels. Perhaps the thousands of pipeline protesters in front of the White House should be spending more time in Ottawa.

The promise of 20,000 new jobs is questionable. Most would be temporary and probably in other countries. The State Department puts the number of created U.S. jobs closer to 6,000. But no matter. The Ogallala aquifer nourishing the people and economy of this irreplaceable ecosystem isn't worth 200,000 jobs.

The Obama administration gets the final say on this project. Its deciders should put their boots on this sandy ground, look up at the stars flooding the big sky and ask the locals about their lives and livelihoods. The pros and cons of Keystone XL pipeline would not balance so nicely if they did.