Cho Oyu | 2013 NW side

A USA expedition to Cho Oyu in 2013 via NW side, led by Dan Mazur. Summit reached on 26th September 2013. 9 members recorded.

Expedition Details

Field	Value
ID	8203
Imported	2026-03-06 18:04:49.359634
Expedition ID	CHOY13303
Peak ID	CHOY
Year	2013
Season	3
Host Country	2
Route 1	NW side
Route 2	-
Route 3	-
Route 4	-
Nationality	USA
Leaders	Dan Mazur
Sponsor	SummitClimb Cho Oyu Expedition 2013
Success 1	True
Success 2	False
Success 3	False
Success 4	False
Ascent 1	-
Ascent 2	-
Ascent 3	-
Ascent 4	-
Claimed	False
Disputed	False
Countries	Finland, Germany, Netherlands, UK
Approach	-
Basecamp Date	2013-09-07
Summit Date	2013-09-26
Summit Time	0900
Summit Days	19
Total Days	22
Termination Date	2013-09-29
Termination Reason	1
Termination Notes	-
High Point (m)	8188
Traverse	False
Ski	False
Paraglide	False
Camps	3
Fixed Rope (m)	1800
Total Members	7
Summit Members	6
Member Deaths	0
Total Hired	2
Summit Hired	2
Hired Deaths	0
No Hired	False
O2 Used	True
O2 None	False
O2 Climb	True
O2 Descent	False
O2 Sleep	True
O2 Medical	False
O2 Taken	False
O2 Unknown	False
Other Summits	-
Campsites	BC(07/09,4900m),ABC(10/09,5690m),C1(15/09,6400m),C1.5(17/09,6800m),C2(24/09,7100m),C3(25/09,7500m),Smt(26/09)
Route Notes	Six of the team's seven members went to the top. The seventh member, Zachary, went to the last camp C3 with the team, but then stayed there while the others summited. Apparently he was not mentally prepared for the final push -- no motivation for a summit bid; he was not using oxygen. The summit party left C3 at 2:00 am on 26 September. They were Grieve, Landmann, Mazur, Olsen, Sunell, Van der Hoeven, Ang Pasang and Jangbu. They reached the top between 9:00 am (Grieve and Jangbu) and 11:00 am (Landmann with Mazur and Ang Pasang accompanying him as Landmann was slow; he was not using oxygen). The weather was excellent. The summiters descended to C2 for the night; they reached there at 6:30 pm. The whole expedition was together in ABC on 27 September and left the mountain on the 29th. Oxygen was used by Grieve, Mazur and Olsen from C2 to the summit to C2. There was an avalanche on 17 September which injured some other expeditions' Sherpas, but this team was untouched. Sherpas: Ang Pasang Sherpa, 15/6/84, Patle, Everest X2 Jangbu Sherpa, 24/5/67, Patle, Everest X7, Cho Oyu X4, Lhotse X1
Accidents	-
Achievement	-
Agency	Everest Parivar
Commercial Route	True
Standard Route	True
Primary Route	False
Primary Member	False
Primary Reference	False
Primary ID	-
Checksum	2462175
Year	2013
Summit Success	True
O2 Summary	Used
Route (lowercase)	nw side

Members

Field	Value
ID	59871
Imported	2026-03-06 18:06:05.675609
Expedition ID	CHOY13303
Member ID	02
Peak ID	CHOY
Year	2013
Season	3
First Name	James Andrew
Last Name	Grieve
Sex	M
Age	0
Birth Date	-
Year of Birth	1963
Calculated Age	50
Citizenship	UK
Status	Climber
Residence	Kinross, Scotland
Occupation	Electrical engineer
Leader	False
Deputy	False
Basecamp Only	False
Not to BC	False
Support	False
Disabled	False
Hired	False
Sherpa	False
Tibetan	False
Summit Success	True
Claimed	False
Disputed	False
Solo	False
Traverse	False
Ski	False
Paraglide	False
Speed	False
High Point (m)	True
Personal High Point (m)	8188
Summit Date 1	2013-09-26
Summit Date 2	-
Summit Date 3	-
Summit Time 1	0900
Summit Time 2	-
Summit Time 3	-
Route 1	1
Route 2	0
Route 3	0
Ascent 1	0
Ascent 2	0
Ascent 3	0
O2 Used	True
O2 None	False
O2 Climb	True
O2 Descent	False
O2 Sleep	True
O2 Medical	False
O2 Notes	From C2 to smt to C2
Death	False
Death Date	-
Death Time	-
Death Type	0
Death Height (m)	0
Death Class	0
AMS	False
Weather	False
Injury	False
Injury Date	-
Injury Time	-
Injury Type	0
Injury Height (m)	0
Death Notes	-
Member Notes	-
Necrology	-
Summit Bid	5
Summit Term	1
HCN	0
Checksum	2436169
Summit Note 1	-
Summit Note 2	-
Summit Note 3	-
Death Route	-
Name (lowercase)	james andrew grieve
Year of Birth	1963
Year	2013
Age at Expedition	50
Role	Member

Field	Value
ID	59872
Imported	2026-03-06 18:06:05.675609
Expedition ID	CHOY13303
Member ID	03
Peak ID	CHOY
Year	2013
Season	3
First Name	Juergen Michael
Last Name	Landmann
Sex	M
Age	0
Birth Date	-
Year of Birth	1969
Calculated Age	44
Citizenship	Germany
Status	Climber
Residence	Langenwetzendorf, Thuringia, Germany
Occupation	Plumber
Leader	False
Deputy	False
Basecamp Only	False
Not to BC	False
Support	False
Disabled	False
Hired	False
Sherpa	False
Tibetan	False
Summit Success	True
Claimed	False
Disputed	False
Solo	False
Traverse	False
Ski	False
Paraglide	False
Speed	False
High Point (m)	True
Personal High Point (m)	8188
Summit Date 1	2013-09-26
Summit Date 2	-
Summit Date 3	-
Summit Time 1	1100
Summit Time 2	-
Summit Time 3	-
Route 1	1
Route 2	0
Route 3	0
Ascent 1	0
Ascent 2	0
Ascent 3	0
O2 Used	False
O2 None	True
O2 Climb	False
O2 Descent	False
O2 Sleep	False
O2 Medical	False
O2 Notes	-
Death	False
Death Date	-
Death Time	-
Death Type	0
Death Height (m)	0
Death Class	0
AMS	False
Weather	False
Injury	False
Injury Date	-
Injury Time	-
Injury Type	0
Injury Height (m)	0
Death Notes	-
Member Notes	-
Necrology	-
Summit Bid	5
Summit Term	1
HCN	0
Checksum	2438347
Summit Note 1	-
Summit Note 2	-
Summit Note 3	-
Death Route	-
Name (lowercase)	juergen michael landmann
Year of Birth	1969
Year	2013
Age at Expedition	44
Role	Member

Field	Value
ID	59873
Imported	2026-03-06 18:06:05.675609
Expedition ID	CHOY13303
Member ID	01
Peak ID	CHOY
Year	2013
Season	3
First Name	Daniel Lee (Dan)
Last Name	Mazur
Sex	M
Age	0
Birth Date	-
Year of Birth	1960
Calculated Age	52
Citizenship	USA
Status	Leader
Residence	Longbranch, Washington
Occupation	House builder
Leader	True
Deputy	False
Basecamp Only	False
Not to BC	False
Support	False
Disabled	False
Hired	False
Sherpa	False
Tibetan	False
Summit Success	True
Claimed	False
Disputed	False
Solo	False
Traverse	False
Ski	False
Paraglide	False
Speed	False
High Point (m)	True
Personal High Point (m)	8188
Summit Date 1	2013-09-26
Summit Date 2	-
Summit Date 3	-
Summit Time 1	1100
Summit Time 2	-
Summit Time 3	-
Route 1	1
Route 2	0
Route 3	0
Ascent 1	0
Ascent 2	0
Ascent 3	0
O2 Used	True
O2 None	False
O2 Climb	True
O2 Descent	False
O2 Sleep	True
O2 Medical	False
O2 Notes	From C2 to smt to C2
Death	False
Death Date	-
Death Time	-
Death Type	0
Death Height (m)	0
Death Class	0
AMS	False
Weather	False
Injury	False
Injury Date	-
Injury Time	-
Injury Type	0
Injury Height (m)	0
Death Notes	-
Member Notes	-
Necrology	-
Summit Bid	5
Summit Term	1
HCN	0
Checksum	2435197
Summit Note 1	-
Summit Note 2	-
Summit Note 3	-
Death Route	-
Name (lowercase)	daniel lee (dan) mazur
Year of Birth	1960
Year	2013
Age at Expedition	53
Role	Leader

Field	Value
ID	59874
Imported	2026-03-06 18:06:05.675609
Expedition ID	CHOY13303
Member ID	04
Peak ID	CHOY
Year	2013
Season	3
First Name	Matthew
Last Name	Olsen
Sex	M
Age	0
Birth Date	-
Year of Birth	1986
Calculated Age	27
Citizenship	USA
Status	Climber
Residence	Eaton, Colorado
Occupation	Instructor, teacher
Leader	False
Deputy	False
Basecamp Only	False
Not to BC	False
Support	False
Disabled	False
Hired	False
Sherpa	False
Tibetan	False
Summit Success	True
Claimed	False
Disputed	False
Solo	False
Traverse	False
Ski	False
Paraglide	False
Speed	False
High Point (m)	True
Personal High Point (m)	8188
Summit Date 1	2013-09-26
Summit Date 2	-
Summit Date 3	-
Summit Time 1	-
Summit Time 2	-
Summit Time 3	-
Route 1	1
Route 2	0
Route 3	0
Ascent 1	0
Ascent 2	0
Ascent 3	0
O2 Used	True
O2 None	False
O2 Climb	True
O2 Descent	False
O2 Sleep	True
O2 Medical	False
O2 Notes	From C2 to smt to C2
Death	False
Death Date	-
Death Time	-
Death Type	0
Death Height (m)	0
Death Class	0
AMS	False
Weather	False
Injury	False
Injury Date	-
Injury Time	-
Injury Type	0
Injury Height (m)	0
Death Notes	-
Member Notes	-
Necrology	-
Summit Bid	5
Summit Term	1
HCN	0
Checksum	2444629
Summit Note 1	-
Summit Note 2	-
Summit Note 3	-
Death Route	-
Name (lowercase)	matthew olsen
Year of Birth	1986
Year	2013
Age at Expedition	27
Role	Member

Field	Value
ID	59875
Imported	2026-03-06 18:06:05.675609
Expedition ID	CHOY13303
Member ID	05
Peak ID	CHOY
Year	2013
Season	3
First Name	Matti Antero
Last Name	Sunell
Sex	M
Age	0
Birth Date	-
Year of Birth	1963
Calculated Age	50
Citizenship	Finland
Status	Climber
Residence	Helsinki, Finland
Occupation	Teacher
Leader	False
Deputy	False
Basecamp Only	False
Not to BC	False
Support	False
Disabled	False
Hired	False
Sherpa	False
Tibetan	False
Summit Success	True
Claimed	False
Disputed	False
Solo	False
Traverse	False
Ski	False
Paraglide	False
Speed	False
High Point (m)	True
Personal High Point (m)	8188
Summit Date 1	2013-09-26
Summit Date 2	-
Summit Date 3	-
Summit Time 1	-
Summit Time 2	-
Summit Time 3	-
Route 1	1
Route 2	0
Route 3	0
Ascent 1	0
Ascent 2	0
Ascent 3	0
O2 Used	False
O2 None	True
O2 Climb	False
O2 Descent	False
O2 Sleep	False
O2 Medical	False
O2 Notes	-
Death	False
Death Date	-
Death Time	-
Death Type	0
Death Height (m)	0
Death Class	0
AMS	False
Weather	False
Injury	False
Injury Date	-
Injury Time	-
Injury Type	0
Injury Height (m)	0
Death Notes	-
Member Notes	-
Necrology	-
Summit Bid	5
Summit Term	1
HCN	0
Checksum	2436113
Summit Note 1	-
Summit Note 2	-
Summit Note 3	-
Death Route	-
Name (lowercase)	matti antero sunell
Year of Birth	1963
Year	2013
Age at Expedition	50
Role	Member

Field	Value
ID	59876
Imported	2026-03-06 18:06:05.675609
Expedition ID	CHOY13303
Member ID	06
Peak ID	CHOY
Year	2013
Season	3
First Name	Jan-Jilles
Last Name	Van der Hoeven
Sex	M
Age	0
Birth Date	-
Year of Birth	1966
Calculated Age	47
Citizenship	Netherlands
Status	Climber
Residence	Madrid, Spain
Occupation	Senior staff of UN mission to Spain
Leader	False
Deputy	False
Basecamp Only	False
Not to BC	False
Support	False
Disabled	False
Hired	False
Sherpa	False
Tibetan	False
Summit Success	True
Claimed	False
Disputed	False
Solo	False
Traverse	False
Ski	False
Paraglide	False
Speed	False
High Point (m)	True
Personal High Point (m)	8188
Summit Date 1	2013-09-26
Summit Date 2	-
Summit Date 3	-
Summit Time 1	-
Summit Time 2	-
Summit Time 3	-
Route 1	1
Route 2	0
Route 3	0
Ascent 1	0
Ascent 2	0
Ascent 3	0
O2 Used	False
O2 None	True
O2 Climb	False
O2 Descent	False
O2 Sleep	False
O2 Medical	False
O2 Notes	-
Death	False
Death Date	-
Death Time	-
Death Type	0
Death Height (m)	0
Death Class	0
AMS	False
Weather	False
Injury	False
Injury Date	-
Injury Time	-
Injury Type	0
Injury Height (m)	0
Death Notes	-
Member Notes	-
Necrology	-
Summit Bid	5
Summit Term	1
HCN	0
Checksum	2437252
Summit Note 1	-
Summit Note 2	-
Summit Note 3	-
Death Route	-
Name (lowercase)	jan-jilles van der hoeven
Year of Birth	1966
Year	2013
Age at Expedition	47
Role	Member

Field	Value
ID	59877
Imported	2026-03-06 18:06:05.675609
Expedition ID	CHOY13303
Member ID	07
Peak ID	CHOY
Year	2013
Season	3
First Name	William Bernard (Bill)
Last Name	Zachary
Sex	M
Age	0
Birth Date	-
Year of Birth	1948
Calculated Age	65
Citizenship	USA
Status	Climber
Residence	Berkeley, California
Occupation	Retired teacher
Leader	False
Deputy	False
Basecamp Only	False
Not to BC	False
Support	False
Disabled	False
Hired	False
Sherpa	False
Tibetan	False
Summit Success	False
Claimed	False
Disputed	False
Solo	False
Traverse	False
Ski	False
Paraglide	False
Speed	False
High Point (m)	False
Personal High Point (m)	7500
Summit Date 1	2013-09-25
Summit Date 2	-
Summit Date 3	-
Summit Time 1	-
Summit Time 2	-
Summit Time 3	-
Route 1	1
Route 2	0
Route 3	0
Ascent 1	0
Ascent 2	0
Ascent 3	0
O2 Used	False
O2 None	True
O2 Climb	False
O2 Descent	False
O2 Sleep	False
O2 Medical	False
O2 Notes	-
Death	False
Death Date	-
Death Time	-
Death Type	0
Death Height (m)	0
Death Class	0
AMS	False
Weather	False
Injury	False
Injury Date	-
Injury Time	-
Injury Type	0
Injury Height (m)	0
Death Notes	-
Member Notes	-
Necrology	-
Summit Bid	3
Summit Term	7
HCN	0
Checksum	2430738
Summit Note 1	-
Summit Note 2	-
Summit Note 3	-
Death Route	-
Name (lowercase)	william bernard (bill) zachary
Year of Birth	1948
Year	2013
Age at Expedition	65
Role	Member

Field	Value
ID	59878
Imported	2026-03-06 18:06:05.675609
Expedition ID	CHOY13303
Member ID	08
Peak ID	CHOY
Year	2013
Season	3
First Name	Ang Pasang
Last Name	Sherpa
Sex	M
Age	0
Birth Date	-
Year of Birth	1984
Calculated Age	29
Citizenship	Nepal
Status	H-A Worker
Residence	Patle-4, Okhaldhunga
Occupation	-
Leader	False
Deputy	False
Basecamp Only	False
Not to BC	False
Support	False
Disabled	False
Hired	True
Sherpa	True
Tibetan	False
Summit Success	True
Claimed	False
Disputed	False
Solo	False
Traverse	False
Ski	False
Paraglide	False
Speed	False
High Point (m)	True
Personal High Point (m)	8188
Summit Date 1	2013-09-26
Summit Date 2	-
Summit Date 3	-
Summit Time 1	1100
Summit Time 2	-
Summit Time 3	-
Route 1	1
Route 2	0
Route 3	0
Ascent 1	0
Ascent 2	0
Ascent 3	0
O2 Used	False
O2 None	True
O2 Climb	False
O2 Descent	False
O2 Sleep	False
O2 Medical	False
O2 Notes	-
Death	False
Death Date	-
Death Time	-
Death Type	0
Death Height (m)	0
Death Class	0
AMS	False
Weather	False
Injury	False
Injury Date	-
Injury Time	-
Injury Type	0
Injury Height (m)	0
Death Notes	-
Member Notes	-
Necrology	-
Summit Bid	5
Summit Term	1
HCN	0
Checksum	2443817
Summit Note 1	-
Summit Note 2	-
Summit Note 3	-
Death Route	-
Name (lowercase)	ang pasang sherpa
Year of Birth	1984
Year	2013
Age at Expedition	29
Role	Hired

Field	Value
ID	59879
Imported	2026-03-06 18:06:05.675609
Expedition ID	CHOY13303
Member ID	09
Peak ID	CHOY
Year	2013
Season	3
First Name	Jangbu
Last Name	Sherpa
Sex	M
Age	0
Birth Date	-
Year of Birth	1967
Calculated Age	46
Citizenship	Nepal
Status	H-A Worker
Residence	Patle-4, Okhaldhunga
Occupation	-
Leader	False
Deputy	False
Basecamp Only	False
Not to BC	False
Support	False
Disabled	False
Hired	True
Sherpa	True
Tibetan	False
Summit Success	True
Claimed	False
Disputed	False
Solo	False
Traverse	False
Ski	False
Paraglide	False
Speed	False
High Point (m)	True
Personal High Point (m)	8188
Summit Date 1	2013-09-26
Summit Date 2	-
Summit Date 3	-
Summit Time 1	0900
Summit Time 2	-
Summit Time 3	-
Route 1	1
Route 2	0
Route 3	0
Ascent 1	0
Ascent 2	0
Ascent 3	0
O2 Used	False
O2 None	True
O2 Climb	False
O2 Descent	False
O2 Sleep	False
O2 Medical	False
O2 Notes	-
Death	False
Death Date	-
Death Time	-
Death Type	0
Death Height (m)	0
Death Class	0
AMS	False
Weather	False
Injury	False
Injury Date	-
Injury Time	-
Injury Type	0
Injury Height (m)	0
Death Notes	-
Member Notes	4th ascent of Cho Oyu
Necrology	-
Summit Bid	5
Summit Term	1
HCN	0
Checksum	2437603
Summit Note 1	-
Summit Note 2	-
Summit Note 3	-
Death Route	-
Name (lowercase)	jangbu sherpa
Year of Birth	1967
Year	2013
Age at Expedition	46
Role	Hired

9 recorded members.

Name	Sex	Year of Birth	Citizenship	Status	Residence	Occupation
James Andrew Grieve	M	1963	UK	Climber	Kinross, Scotland	Electrical engineer	Details Other expeditions
Juergen Michael Landmann	M	1969	Germany	Climber	Langenwetzendorf, Thuringia, Germany	Plumber	Details Other expeditions
Daniel Lee (Dan) Mazur	M	1960	USA	Leader	Longbranch, Washington	House builder	Details Other expeditions
Matthew Olsen	M	1986	USA	Climber	Eaton, Colorado	Instructor, teacher	Details Other expeditions
Matti Antero Sunell	M	1963	Finland	Climber	Helsinki, Finland	Teacher	Details Other expeditions
Jan-Jilles Van der Hoeven	M	1966	Netherlands	Climber	Madrid, Spain	Senior staff of UN mission to Spain	Details Other expeditions
William Bernard (Bill) Zachary	M	1948	USA	Climber	Berkeley, California	Retired teacher	Details Other expeditions
Ang Pasang Sherpa	M	1984	Nepal	H-A Worker	Patle-4, Okhaldhunga	-	Details Other expeditions
Jangbu Sherpa	M	1967	Nepal	H-A Worker	Patle-4, Okhaldhunga	-	Details Other expeditions

References

Field	Value
ID	8872
Imported	2026-03-06 18:06:36.307770
Expedition ID	CHOY13303
Reference ID	01
Year	2013
Type	5
Journal	-
Author	-
Title	http://www.summitclimb.com/new/default.asp?linktype=r&nid=233
Publisher	-
Publication Date	-
Language	-
Citation	-
Yak 94	-
Notes	-

1 recorded references.

Expedition ID	Journal	Author	Title	Publisher	Citation	Yak 94
CHOY13303	-	-	http://www.summitclimb.com/new/default.asp?linktype=r&nid=233	-	-	-