Page 65 - 2002 DT 12 issues

Wha t’ s Insi d e !
Featured Articles
Our Changeable Weather...........................1
Boot Tracks.................................................5
Special
Quiz............................................................7

Departments
September 2002 News & Notes............................................2
Programs & Hikes........................................4
Desk Schedule............................................6
Bulletin Board.............................................8

Our Changeable ○ ○ When the earliest migrants, furred ○ around 10,000 years ago came so im-
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and hooded, emerged from the ice pack, ○ perceptibly, none of the generations of
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Weather ○ ○ they found a Garden of Eden only 300 ○ ○ Ancient Ones ever was aware of it. The
miles south. The glaciers that glowered ○ ○ glaciers began to shrink in height and
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by Jack Ryan ○
○ over them with unrelenting cold had cre- ○ breadth. As they retreated into Canada,
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○ ated a gentle valley ready to fulfill the ○ they ceased providing the evaporation
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hew, it’s been a hot summer. ○ needs of hunter-gathers. ○ ○ that produced humidity and clouds that
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But when was it not hot in the ○ In the summer heat, the glaciers’ sur- ○ ○ created rain that fed flora and fauna and
WLas Vegas Valley in summer? ○ ○ face would melt. The evaporation would ○ pluvial lakes. In 3,000 years, Eden would
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About 12,000 years ago, that’s when. ○ ○ form clouds and humidity. The clouds ○ be no more than a mythical time in the
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Residents of the valley—migrants just as ○ would burst with moisture and create a ○ memories of the Ancient Ones’ descen-
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many 21st Century residents are—en- ○ chain of pluvial lakes (lakes entirely de- ○ dants.
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joyed an almost idyllic environment. ○ pendent on rain water). We see
Summer temperatures rarely went above ○ ○ remnants of these lakes today
85˚ F. Hazy clouds shrouded the scorch- ○ ○ as long stretches of dry
ing sun. The Ancient Ones doubtlessly ○ sand beds. The Las Vegas
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complained of the high humidity, and ○ Valley is known geo-
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looked forward to the frequent showers ○ graphically as Dry Lakes
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of summer. The average rainfall then was ○ Valley. The glaciers even
16 inches a year on the valley floor com- ○ ○ moderated the winters.
pared to 4 inches today. ○ Their towering size
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Seattle-like summers were generally ○ formed a protective wall
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pleasant. Winters weren’t much different ○ against freezing Arctic
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from today’s; temperatures were a few ○ blasts.
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degrees warmer and winds less blustery. ○ The Las Vegas Valley was verdant ○ Eatable plants became seared by the
The principal reason for the temperate ○ ○ with a canopy of pinon pines and juniper ○ ○ sun or wilted for lack of rain. The valley
climate of 12,000 years ago was glaciers ○ trees, and the topsoil was rich with nutri- ○ ○ floor was denuded of pine and juniper as
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that stretched from ocean to ocean and ○ tious grasses and plants that we now ○ the treeline pulled back to the cooler
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reached as far south in our region as Reno associate with the grazing plains. The ○ mountain elevations. The big game found
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and Carson City. At their thickest they ancient hunters-gathers picked grapes, ○ food scarcer with each generation. To-
rose 2 miles. The Ancient Ones had mi- ○ tubers, and nuts, and stalked mastodons ○ ward the end of the era the young people
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grated through and around the glaciers ○ and mammoths. Camels, horses, and gi- ○ of the valley listened to stories of great
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from Siberia, crossing on a land bridge ○ ant sloths roamed through the woodland. hunts by their ancestors and would have
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sometimes 300 miles wide until it was ○ Flamingos drank at the lakes. Droughts derided them except for those huge
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swallowed up by the Bering Strait. They ○ occurred, but rains and snow melt in the bones and skulls buried in the dry lake
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used corridors through the glaciers or ○ ○ high mountains packed tons of water un- ○ ○ beds.
passed along a broad flat coastline cre- ○ ○ derground and springs tided the popula- ○ ○
ated when the glaciers sucked ○ ○ tion though the dry spells. ○
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up ocean waters to make ice. ○ But not for long. What occurred ○ Weather, continued on page 6