Numbers Refer to Number of Persons Involved





1951-71

1959-71

1972





U.S.A.

CAN.

U.S.A.

CAN.



Terrain



Rock

1009

74

122

25



Snow

533

80

49

15



River

4

0

0

0



Unknown

1

2

1

0



Ascent or Descent



Ascent

758

90

90

25



Descent

696

60

71

13



Unknown

93

6

11

2



Immediate Cause



Fall or slip on rock

552

42

60

11



Failure of piton

35

2

6

0



Falling rock or object

135

19

20

8



Failure of rappel

66

2

12

1



Slip on snow or ice

216

27

17

0



Fall into crevasse

32

8

0

3



Loss of control — Voluntary glissade

60

5

7

0



Avalanche

96

31

5

7



Lightning

25

3

6

0



Skiing

5

2

1

1



Faulty use of crampons

8

1

2

0



Exceed abilities

110

5

10

0



Exposure and/or Exhaustion

82

1

6

1



Heat prostration

3

0

0

0



Unknown

9

2

3

0



Failure to follow route

3

0

1

0



Stranded

79

3

12

8



Illness Medical (incl. Pulm. Edema and Frostbite)

29

3

4

0



Prussik knot slipped

2

0

0

0



Contributory Causes



Climbing unroped

404

29

55

14



Climbing alone

109

13

23

1



Exceeding abilities

(inexperienced)

360

44

50

13



Darkness

35

2

8

1



Inadequate equipment

156

7

32

9



Old rope

8

1

0

0



Piton failure

40

2

6

1





1951-71

1959-71

1972





U.S.A.

CAN.

U.S.A.

CAN.



Bad weather

55

6

17

1



Exposure and/or Exhaustion

32

1

4

0



Party separated

30

2

4

4



Age of Individuals



Boys

5

0

0

0



Under 15

57

4

6

0



15-20

535

35

68

7



21-25

344

31

48

7



26-30

186

35

17

10



31-35

106

9

8

7



Over 35

170

21

12

6



Unknown

144

21

13

3



Affiliation with Climbing Groups



Unaffiliated

536

26

56

11



Not stated

448

42

79

11



Member of Mountaineering Club

563

88

37

18



Estimate of Experience



None or little

728

56

78

15



Moderate

409

35

46

12



Experienced

244

50

34

10



Unknown

166

15

14

3



Month of Year



January

49

2

5

0



February

83

8

6

4



March

79

2

10

1



April

87

3

12

0



May

129

9

21

2



June

179

25

22

6



July

295

56

19

9



August

279

39

35

16



September

155

6

19

1



October

86

2

8

1



November

71

1

5

0



December

47

1

10

0



Unknown

8

2

0

0