1. The document discusses the landscape and life in Utah during the last Ice Age between 10,000 to 30,000 years ago when large glaciers and Lake Bonneville covered much of the state. 2. Lake Bonneville was a prehistoric lake that existed in the Great Basin during the last ice age. At its largest extent, it covered much of northern and central Utah and small parts of Nevada and Idaho. 3. The landscape was shaped by glacial features such as cirques, moraines, and U-shaped valleys carved by the large glaciers. Glacial erratics and polish on rock surfaces provide evidence of past glacial activity.

1. Intro- The Ice Age in Utah The Ice Age in Utah The landscape and life in Utah during the most recent Ice Age in Utah 10,000 to 30,000 years ago. Lake Bonneville glaciers Salt Lake City 18,000 years ago . in Utah

2. Ice Ages Throughout Geologic Time Average Global Temperature ( 0 C) Figure modified after C.R. Scotese PALEOMAP Project (www.scotese.com) Quaternary 12° 22° 17° Ice Age Ice Age Ice Age Ice Age

4. Milankovitch Cycles Eccentricity 90,000 to 100,000 years Precession 19,000 to 23,000 years Obliquity (Axial Tilt) 41,000 years Figures modified after Matt Beedle, Montana Sate University. ~5% ~0%

5. Lake Bonneville and Ice Coverage in Utah During the Late Pleistocene ~18,000 years ago Lake Bonneville Uinta Mountains Wasatch Range

6. Lake Bonneville ~18,000 years ago Utah Salt Lake Delta

7. The Rise and Fall of Lake Bonneville Bonneville Level 18,000 years ago Gilbert Level 12,000 years ago Provo Level 17,000 years ago Stansbury Level 24,000 years ago Hydrograph of Lake Bonneville Great Salt Lake today

8. Stansbury Shoreline Red Rock Pass ~24,000 years ago Stansbury Island Ogden Delta Nephi Provo Salt Lake UT ID NV

9. Bonneville Shoreline ~18,000 years ago Point of the Mountain Ogden Delta Nephi Provo Salt Lake UT ID NV Red Rock Pass

10. Provo Shoreline ~17,000 years ago Ogden Delta Nephi Provo Salt Lake UT ID NV Red Rock Pass

11. Gilbert Shoreline ~12,000 years ago Ogden Delta Nephi Provo Salt Lake UT ID NV Red Rock Pass

12. Great Salt Lake Today Ogden Delta Nephi Provo Salt Lake UT ID NV Red Rock Pass

13. Shorelines of Lake Bonneville at Antelope Island Provo Stansbury Gilbert Bonneville Unnamed shoreline Unnamed shoreline

14. Bonneville Shoreline at Point of the Mountain Paragliders

15. Bonneville Shoreline at Point of the Mountain Bonneville Shoreline at the “U”

16. Stockton Bar, Utah Modern Barrier Bar and Spit Lake Bonneville Barrier Bar and Spit Kiawah Island, South Carolina

17. Lake Bonneville Spits Older spit Younger spit Contact surface

18. Lake Bonneville Deep-Water Sediments Laminations

19. Tufa on the Provo Shoreline Tufa on Quartzite

20. Lake Bonneville Delta Sediment Transport Direction

21. Provo Shoreline Wave-Cut Platform Wave Direction

22. Bonneville Salt Flats Provo Shoreline Bonneville Shoreline Salt

23. Modern Glaciers Alaska Devil’s Desk Glacier Halo Glacier, Cook Inlet

24. Holgate Glacier, Alaska

25. Glacial Cirques Uinta Mountains Convict Lake, Sierra Nevada Mountains Glacial Cirque Glacial Cirque

26. U-shaped Glacial Canyons Little Cottonwood Canyon Yosemite Valley Glacier National Park

27. Mill Creek Canyon “V-shaped” Stream- eroded canyon Little Cottonwood Canyon “U-shaped” Glacier- eroded canyon

28. Glacial Scenery at Alta, Utah U-shaped Valley Arêtes

29. Moraines Chugach Mountains, Alaska Image by Michael Collier Medial Moraine Image by Bruce Molnia, Terra Photographics

30. Glacial Features at Little Cottonwood Canyon Fault Scarps Trimline Moraines U-Shaped Valley

31. Bells Canyon, Utah Lateral Moraine Fault Scarp

32. Glacial Erratics Voyageurs National Park, Minnesota Denali National Park, Alaska Person

33. Little Cottonwood Canyon Glacial Erratics

34. Glacial Polish and Grooves Grooves and polish on bedrock Glacier National Park, Montana Striations

35. Life in Utah During the Ice Age

36. Life in Utah at the end of the Ice Age

37. Assorted Lake Bonneville Mollusks

38. Hunting for Gastropods (Snails)

39. Bonneville Cutthroat Trout Known Distribution Today are isolated in streams that once drained into Lake Bonneville.

40. Utah’s Giant Ice Age Birds Teratornis- “ giant condor” Teratornis skeleton Endangered California Condor Teratornis skull

41. Ice Age Land Bridges and Mammal Migrations

42. Ice Age Elephants Mammoth Mastodon Detail from Joseph S. Venus mural, College of Eastern Utah (CEU) Prehistoric Museum, Price, Utah The Huntington Mammoth ( Mammathus columbi ) skeleton at the CEU Prehistoric Museum

43. Mammoth & Elephants vs. Mastodons Columbian Mammoth ( M. columbi ) American Mastodon ( Mammut americanum ) Elephants and mammoths have high skulls, while mastodons have low skulls. Elephants and mammoths have low, highly enfolded teeth for grazing, while mastodons have high crested teeth for browsing leaves . Elephants and mammoths are tall, while mastodons are shorter with more massive bodies .

44. Saber-toothed Cat Skeletal reconstruction and detail from Joseph S. Venus mural, CEU Prehistoric Museum, Price, Utah Smilodon fatalis

45. Giant Ground Sloth Skeletal reconstruction and detail from Joseph S. Venus mural, CEU Prehistoric Museum, Price, Utah

46. Other Extinct Ice Age Mammals Extinct Musk Ox Extinct Long-Horned Bison Camels, together with native horses, went extinct in North America at the end of the Ice Age

47. Mountain mammals that lived in Ice Age Lowlands The American pika, Ochotona princeps , The wolverine, Gulo gulo