The Strange and Beautiful World of Arches National Park

01This week, on our national parks journey, we travel to Utah.

02The western state is home to several of the most popular national parks in America.

03Today, we travel to the eastern part of the state.

04We visit a park filled with strange and beautiful colored rock formations.

05These formations have been created over millions of years.

06They curve and narrow and balance on top of one another.

07Some are extremely thin.

08Others have huge cracks yet remain standing.

09Many of the rock formations seem to ignore the rules of gravity.

10Welcome to Arches National Park.

11Arches are formations that look like half a circle standing up.

12Sometimes they create a curved bridge between two large rocks.

13Arches National Park contains the most natural rock arches of any place on Earth.

14The smallest arches are less than a meter across.

15The largest, called Landscape Arch, measures 93 meters from one base of the arch to the other.

16Water and ice, extreme temperatures, and many layers of salt underground created these rock formations over hundreds of millions of years.

17The huge amount of salt is the remains of an ancient sea.

18It covered the area around 300 million years ago.

19As time passed, the area filled with material left by rivers.

20Rocks buried the area.

21This created pressure on the underground salt bed.

22Salt under pressure moves easily.

23It is not stable.

24The thick cover of rock created pressure on the salt.

25It moved this way and that, making the rock layers above move as well.

26A soft rock called sandstone moved upwards.

27It met with other, harder rocks.

28These sandstone structures continued to grow for about 150 million years.

29Scientists say water is the most important element in creating arches.

30Water destroys the chemicals that keep rock particles together.

31The rock breaks as the water freezes and expands.

32Then, the wind blows away the loose rock pieces.

33Erosion from wind and weather slowly removed layers of younger rock.

34Most of the layers of rock seen today are pinkish-red in color.

35The rock is called Entrada sandstone.

36Experts say that most arches seen in the park today developed within the past million years.

37But the land formations continue to change slowly over time.

38But sometimes change happens quickly.

39In 2008, a formation called Wall Arch suddenly collapsed.

40Thousands of tons of sandstone crashed to the ground, creating a thunderous noise.

41It is not easy to predict when arches might collapse.

42Wall arch was not as thin as landscape arch, for example.

43Wall arch also did not have visible cracks.

44But many tiny breaks within the stone made the arch weaker than others.

45Some formations within the park look as though the gentlest wind could send huge pieces of rock crashing to the ground.

46These are called balanced rocks.

47The most famous of all is simply called balanced rock.

48This sandstone rock is the size of three school buses.

49It sits on top of a tower of darker rock called mudstone.

50The formation is about 39 meters tall.

51This bottom rock narrows sharply where it connects to the sandstone rock on top.

52Scientists call this a bridge.

53Mudstone weathers much more quickly than sandstone.

54One day, far in the future, balanced rock will no longer be balanced.

55Just as wall arch did, balanced rock will collapse.

56The names of the rock formations give you information about their appearance or structure.

57The most famous arch within the park is named delicate arch.

58Delicate means easily broken or damaged, but it can also mean very carefully and beautifully made.

59Delicate arch is a huge freestanding arch.

60It is 19 meters high and 13 meters wide.

61Humans have called it many different names throughout history.

62The name delicate arch first appeared in a 1934 article.

63Scientists described it as the most delicately chiseled arch in the entire area.

64Of the 2,000 stone arches within the park, delicate arch has become a symbol of the state of Utah.

65It is among the most famous geological features in the world.

66Many of arch's famous rock formations are easily seen from the single road that goes through the park.

67But delicate arch is not visible from a car.

68Some visitors choose to walk to two viewpoints.

69But even from the viewpoints, delicate arch is still more than a kilometer away.

70Many visitors choose to hike up to see the famous arch.

71The trail is 5 kilometers.

72It is the most popular hike in the park.

73The walk is difficult and steep.

74It offers no shade.

75The sun is extremely strong.

76In summer months, the temperature can rise to 40 degrees Celsius.

77Park officials tell hikers to take at least 2 liters of water with them.

78In winter months, ice and water can make the sandstone trail extremely slick.

79Along the way, hikers pass a wall of ancient animal drawings created by the Ute Indians.

80These are called petroglyphs.

81Petroglyphs exist throughout the park.

82They are a reminder of the long human history in this harsh environment.

83Before reaching delicate arch, hikers must walk on a long and narrow rock ledge.

84The trail is often crowded with people.

85But most say the heat and crowds are worth it.

86Delicate arch stands alone above a natural sandstone bowl.

87It rises up dramatically from the flat land that surrounds it.

88On one side of the arch, the sandstone gently twists.

89On the other, a severe crack cuts through the narrowing rock.

90Those who hike to its base appreciate and understand why it was once described as delicate.

91Most visitors to Arches National Park would agree that there is no other place quite like it in the world.

92It is quiet and dreamlike.

93Unpredictable and violent.

94Old yet ever-changing.

95A trip to Arches is like visiting another world.

96I'm Ashley Thompson.

97And I'm Katie Weaver.