During the Pleistocene ice age, which ended roughly 10, 000 – 12, 000 years ago, the Sierra Nevada ranges were much wetter.

During the Pleistocene, what would be Leon County emerged and submerged with each glacial and interglacial period.

During the Pleistocene period a snowfield covered the top of the Mount Field plateau which fed glaciers in the surrounding valleys.

During the Pleistocene Epoch continental glaciers scraped away soil and steepened cliffs on hills around this valley, particularly on Mounts Tekoa and Shatterack east of the river, and on Turtle Mountain standing in the middle of the valley.

During the late Pleistocene era, reindeer were found as far south as Nevada and Tennessee in North America and Spain in Europe.

During the Pleistocene it occurred in vast parts of Eurasia, North America and until the middle Pleistocene ( about 1. 5 million years ago ) even in Africa.

During Pleistocene times all these lacustrine basins were occupied by lakes of much greater depth and larger size.

During the Pleistocene, and mostly during the last 50, 000 years, tortoises of the mainland of southern Asia ( Colossochelys atlas ), North and South America, Australia ( Meiolania ), Indonesia, Madagascar ( Dipsochelys ), and even the island of Malta became extinct.

During the very cold Pleistocene climates, all of Denali was solidly frozen.

During the Pleistocene ( c. 1. 8 to 0. 01 mya ), the watershed was extensively modified by continental glaciation.

During the past several thousand years, eruptions of the volcanoes in the Ruiz – Tolima massif have mostly been small, and the pyroclastic flow deposits have been much less voluminous than during the Pleistocene.

During the Late Pleistocene ( 300, 000 years ago ) the gray wolf ( Canis lupus ) crossed into North America on the Bering Strait land bridge and competed with the dire wolf.

During the Pleistocene, the species widely occurred in continental Europe.

During the Pleistocene, 18, 000 years ago, Mount Greylock and the surrounding region were covered by ice sheets up to in thickness.

During the Pleistocene epoch, giant monitor lizards lived in Southeast Asia and Australasia, the best known fossil being the megalania ( Varanus priscus unless it falls in its own genus, in which case it is Megalania prisca ).

During the series of Pleistocene glaciations a succession of ice-sheets moved from northeast to southwest across Anglesey and neighbouring Arfon scouring the underlying rock, the grain of which also runs in this direction.

During the 19th century, villagers in the area digging in the fields discovered a number of bones and used them as " dragon bones " (), a reference to the traditional Chinese medicine practice of grinding up Pleistocene fossils into tonics or poultices.

During the Late Pleistocene, another species probably assignable to the genus, Sarcoramphus fisheri, occurred in Peru.

During the Pleistocene epoch, great continental ice sheets scoured and depressed the shield's surface, leaving a thin covering of glacial material and innumerable lakes and streams.

During warming at the end of the Pleistocene and Early Holocene, the area encompassing Raritan Bay changed from tundra to a landscape dominated by spruce and pine forests.

During the Pleistocene Epoch the Mansfield sandstone bedrock was carved into the current distinct formations by glacial meltwaters and their associated erosion.

During the Pleistocene, giant dormice the size of large rats, such as Leithia melitensis, lived on the islands of Malta and Sicily.

During the last ( Pleistocene ) Ice Age, two lobes of the glacier appear to have parted around the pre-existing plateau and further deepened the lowlands flanking the plateau.

During this precarious period of development the mother should continue to influence the growth of the child's conscience.

During the period from 1 July 1960 through 31 January 1961, additional research affiliations were effected with the U. S. Army Medical Research and Development Command to conduct research in procedures for quantitative electron microscopy, and for the study of biophysical and biological studies of the structure and function of ocular tissue.

During this period, a total of 762 exhibits were presented at 442 medical and scientific meetings.

During the period of this report, 37,470 new cases were entered into the various registries.

During this period, 7,827 teaching sets were distributed on loan.

During the period of this report, 63 panel exhibits depicting the latest developments in medical research were displayed.

During the period, the laboratory rendered centralized macropathological service to qualified requesters.

During the period from 1 July 1960 through 31 January 1961, the Medical Museum was required to move to Temporary Building `` S '' on the Mall from Chase Hall.

During the period of about 4 hours around sunset, skywave transmission conditions are building up until full nighttime conditions prevail ; ;

During the Civil War period Mr. Brown also invented the Brown & Sharpe formed tooth gear cutter, a basic invention which ultimately revolutionized the world's gear manufacturing industry by changing its basic economics.

During this period 7,484,268 members were received, yet the net membership now is only 9,910,741.

During the period of the Iberian Union ( 1580 – 1640 ), Portugal lost influence and power and made new enemies.

During the Romantic period, art came to be seen as " a special faculty of the human mind to be classified with religion and science ".< ref >

During the same period the Georgian states of Colchis and Tabal arose around the Black Sea and central Anatolia respectively.

During this same period, slave-holding border states had more free African-Americans and European immigrants than the lower South, which increased Southern fears that slavery was threatened with rapid extinction in this area.

During this period he published 18 plays and 3 novels, including the murder mystery The Red House Mystery ( 1922 ).

During this period winter sports were slowly introduced: in 1882 the first figure skating championship was held in St. Moritz, and downhill skiing became a trendy sport with English visitors early in the 20th century, as the first ski-lift was installed in 1908 above Grindelwald.

During the post-World War I period ski-lifts were built in Swiss and Austrian towns to accommodate winter visitors, but summer tourism continued to be important ; by the mid-20th century the popularity of downhill skiing increased greatly as it became more accessible and in the 1970s several new villages were built in France devoted almost exclusively to skiing, such a Les Menuires.

During the first 11 months of 2006, net imports grew by 21 percent to $ 1. 95 billion, while exports stood at $ 895 million, up 0. 3 percent from the same period in 2005.

During the first 11 months of 2006, the European Union remained Armenia's largest trading partner, accounting for 34. 4 percent of its $ 2. 85 billion commercial exchange during the 11-month period.

During January – February 2007, Armenia ’ s trade with Russia and other former Soviet republics was $ 205. 6 million ( double the amount from the same period the previous year ), making them the country ’ s number one trading partner.

During this period, spectator attendances dropped and media condemnation increased, but Simpson and Lawry flatly disregarded the public dissatisfaction.

During the Tokugawa period ( 1600 – 1868 ) the Ainu became increasingly involved in trade with Japanese who controlled the southern portion of the island that is now called Hokkaido.

During this period Agamemnon and his brother, Menelaus, took refuge with Tyndareus, King of Sparta.

During the Akkadian period, the Akkadian language became the lingua franca of the Middle East, and was officially used for administration, although the Sumerian language remained as a spoken and literary language.