were expert skiers and they cut back down the shortest route to the Sno cars. A faint audio signal sounded in their right ears from the homing beacons in the snow vehicles. As they shifted directions through the trees, the signal shifted from ear to ear and grew stronger as they neared their cache.

A few minutes later they broke out into the edge of the small clearing with its downed spruce and the two Sno cars. From the carriers they extracted light-weight collapsible plastic domed shelters. A half hour later the domes were joined together by a two-man shelter tube and their sleeping bags were spread in the rear dome. While Alec was shaking out the bags and stowing gear, Troy set up the tiny camp stove in the front dome, broke out the rations and began supper. The detachable, mercury-battery headlight from one of the Sno cars hung from the apogee of the front dome and the other car light was in the sleeping dome.

By the time they had finished eating, the wind had died but the snow continued to fall, piling up around the outside of the plastic dome as it drifted and fell. Its sheltering bulk added to the already near-perfect insulation of the domes. The outer air temperature had fallen to minus fifteen degrees but the temperature below the surface of the snow held at a constant twenty-five degrees above zero and within the front dome with its light and stove, it was a warm seventy-five. The excess heat escaped through a flue tube in the top of the dome.

Both men had stripped down to shorts and T-shirt and now quietly relaxed.

"That's a goodly amount of precip piling up out there," Alec remarked languidly. "God knows we can use it."

"If this keeps up all night," Troy said, "we may have to dig ourselves outta here in the morning." He leaned back and surveyed the rounded roof above him. "Remember what I said this afternoon about nothing ever changing in DivAg?"

Alec nodded.

"Well, sir, here's another fine example of progress halted dead in its tracks," the lanky hydrologist went on. "For centuries the Eskimos have lived through Arctic winters in igloos, made of snow blocks, cut and rounded to form a cave in the snow.

"What's good enough for the Eskimos is good enough for DivAg. Here we are right back in the Ice Age, living in an igloo. If that stove used blubber or seal oil instead of chemical fuel, the picture would be complete."

Alec grinned. "Just because something is old doesn't mean it's no good, Dr. Braden," he said. "The Eskimos proved the efficiency of the igloo. We've just adopted the principle and modernized it. It still works better than any other known snow-weather shelter. But I didn't see you cutting any snow blocks with your skinning knife to build this snug haven, nor crawling for hours on your belly across the snow to sneak up on a seal for your supper."

"Technicalities," Troy scoffed lazily. "The point is, that here were are living almost under the same conditions that the primitive savages of the frozen north lived under for centuries." He belched gently and stretched his long legs luxuriously away from the webbing of the bucket camp chair.

"I must say that you seem to be enjoying it," Alec commented. "Primitive or not, I still like this better than those rat warrens they call cities today."

Nearly two miles above them, the replacement snow gauge, C11902-87, already buried in a half-foot of new snow, sent out a strong and steady signal. At midnight, when both snow hydrologists were sleeping soundly in their bags, hundreds of miles away in regional survey headquarters at Spokane, the huge electronic sequencer began its rapid signal check of each of the thousands of snow gauges in the five-state area of Region Six.

A dozen red lights flicked on among the thousands of green pinpoints of illumination on the huge mural map of the area indicating gauges not reporting due to malfunctions. The technician on duty compared the red lights with the trouble sheet in his hand. He noted two new numbers on the list. When he came to C11902-87, he glanced again at the map. A minute, steady green ray came from the tiny dot in the center of a contour circle that indicated a nameless peak in the Sawtooth Range.

The technician lined out C11902-87 on the trouble chart. "They got to that one in a hurry," he murmured to himself. Another figure had been returned to the accuracy percentage forecasting figures of the huge computers that dictated the lives and luxuries of more than a half a billion Americans.

Water, not gold, now set the standard of living for an overpopulated, overindustrialized continent, where the great automated farms and ranches fought desperately to produce the food for a half billion stomachs while competing with that same half billion for every drop of life-giving moisture that went into the soil.

In the winter, the snows and early fall rains fell in the watershed mountains of the continent, then melted and either seeped into the soil or first trickled, then gushed and finally leaped in freshets down from the highlands to the streams and rivers. As the great cities spread and streamflow waters were dammed and stored and then metered out, there was no longer enough to meet agricultural, industrial and municipal needs.

The cities sent down shaft after shaft into the underground aquifers, greedily sucking the moisture out of the land until each day, each month and each year, the water tables fell deeper and deeper until they, too, were gone, and the land was sucked dry.

There was water in the highlands, in watersheds and spilling unused down to the sea in many areas. Soon the cities and industries sent out great plastisteel arteries to bring the lifeblood of the land to the vast sponges of the factories and showers in home and food-processing plants and landrounits. Water for the machine-precise rows of soy bean plants and for babies' formulas and water for great nuclear power plants and water for a tiny, sixty-fifth floor apartment flower box.

But there was never enough and a nation finally could no longer evade the situation that had been forewarned and foredoomed a century earlier by the pioneers of conservation.

Only by total conservation of every possible drop of moisture could the nation survive, and to conserve, it is first necessary to have an accurate and constantly-current inventory of the substance that is to be conserved.

To the executive branch of the government had come the Secretary of Water Resources, and with the creation of the new cabinet office, the former cabinet posts of Agriculture and Interior were relegated to subordinate and divisional status.

To the thousands upon thousands of trained hydrologists, meteorologists and agronomists of the federal agencies of agriculture, interior and commerce fell the task of manipulating and guiding the delicate balance of the world's water cycle. The snows and rains fell upon the earth, to soak into the land, flow down the streams and rivers to the sea or to the great lakes, and then be returned to the atmosphere to fall again in the ageless cycle of life.

But the happenstance habits of nature were steadily being integrated into the control program of man. The rains and snow still fell where nature intended but man was now there to gauge and guide the moisture in a carefully controlled path through its cycle back to the atmosphere.

An inch or an acre-foot of water falling as snow upon the high mountains was used over and over many times and by many persons before returning to its starting place in the atmosphere.

With the age of nuclear power, the need for hydroelectric sources vanished and with it went the great dams and reservoirs with their vast, wasteful surfaces of open water that evaporated by the thousands of acre-feet before ever being utilized by man. The beds of the great rivers were dry and the