Mark McCaslin

Born : 1969 Cat. M55 Ultrarunner since 2008

DUV-index ?Largest integer N such that the runner has at least N credited races of at least N km.

105

DUV-index+ ?Largest integer N such that the race distances provide at least N complete segments of N km in total. A single long race may therefore contribute several segments. See the DUV-Index tab for the detailed calculation. calculation details

Countries visited ?

Canada

United States

44,0%

Rank quotient ?This runner's calculation uses 103 eligible race(s): Σ(rank − 1) = 3 478; Σ finishers = 7 905. 3 478 / 7 905 × 100 = 44.00%. A win adds 0 to the numerator. Lower is better.

Totals

Ultras completed103

Km — ultra races17 442 km

> 100 km47

> 160 km34

> 200 km19

> 24h55

> 48h24

Longest race651,2 km

25th Sri Chinmoy 6 Day Race — 21/4/2023

Km per year (ultra races)

1 358

2022

2 041

2023

2024

235

2025

2026

Race types (share of distance)

Road57,0%

Trail27,3%

Elim.1,9%

?13,8%

Wins & podiums (ultra)

🏆 Win1

🏆 Win M1

🏅 Top 33

🏅 Top 3 M6

Longest winning streak1

Current streak0

Records

50 km4h41'28 100 km12h19'25 50 mi8h33'36 100 mi21h00'23 12 h96,56 km 24 h166,07 km 48 h198,75 km 6 d651,22 km Backyard15 loops

HISTORY

103 race(s) · 18 split(s) nested

Date		Race	Perf.	Rk
2025
04.10	24h	8th Bear Lake Ultra Race	79.823 km	24
06.06	24h	5th Island Time 24 Hour Race	54.717 km	41
17.05	Backyard Ultra	4th Perfect PR Backyard	100.590 km (15h)	11
2024
05.10	24h	7th Bear Lake Ultra Race	49.889 km	71
2023
11.11	24h	7th The Stinger 24 Hour Race	127.492 km	15
11.11	12h	7th The Stinger 24 Hour Race - 12h Split	92.841 km	11
07.10	24h	6th Bear Lake Ultra Race	114.747 km	22
16.09	50mi	17th Run Rabbit Run 50 Mile Endurance Run	13:16:11 h	103
30.07	50km	4th Kensington Marathon 50km Race	5:30:18 h	10
22.07	Backyard Ultra	5th Ode to Laz Backyard Ultra	53.648 km (8h)	49
16.06	6d	6th Six Days in the Dome - The Redux	591.569 km	7
16.06	50mi	6th Six Days in the Dome - The Redux 50mi Split	9:57:54 h	5
16.06	100km	6th Six Days in the Dome - The Redux 100km Split	13:30:22 h	6
16.06	100mi	6th Six Days in the Dome - The Redux 100mi Split	28:32:34 h	7
20.05	Backyard Ultra	2nd Perfect PR Backyard	53.648 km (8h)	37
13.05	24h	28th Dawn to Dusk to Dawn 24 Hour	85.600 km	21
13.05	50km	28th Dawn to Dusk to Dawn 24 Hour - 50km Split	5:42:12 h	12
13.05	50mi	28th Dawn to Dusk to Dawn 24 Hour - 50mi Split	11:08:04 h	15
21.04	6d	25th Sri Chinmoy 6 Day Race	651.221 km	1 🏆
21.04	24h	25th Sri Chinmoy 6 Day Race - 24h Split	128.747 km	2 🥈
21.04	48h	25th Sri Chinmoy 6 Day Race - 48h Split	214.203 km	4
01.04	33.5mi	17th Kal-Haven Trail Run	5:56:22 h	28
03.03	48h	10th Jackpot Ultra Running Festival 48 Hour Race	178.420 km	14
2022
28.12	6d	38th Across the Years, 6 days	342.297 km	25
12.11	24h	6th The Stinger 24 Hour Race	125.110 km	23
08.10	24h	5th Bear Lake Ultra Race	84.812 km	37
17.09	50mi	16th Run Rabbit Run 50 Mile Endurance Run	14:13:05 h	115
19.06	6d	5th Six Days in the Dome - The Redux	160.974 km	18
21.05	Backyard Ultra	1st Perfect PR Backyard	67.060 km (10h)	22
07.05	24h	27th Dawn to Dusk to Dawn 24 Hour	130.800 km	6
01.04	12h	3rd Vernal Equinox 12 Hour Race	93.341 km	4
18.02	72h	9th Jackpot Ultra Running Festival 72 Hour Race	273.588 km	9
2021
28.12	6d	37th Across the Years, 6 days	563.189 km	10
13.11	24h	5th The Stinger 24 Hour Race	162.559 km	10
09.10	24h	4th Bear Lake Ultra Race	84.812 km	32
24.07	12h	6th Loopty Loop 12 Hour Ultra Trail Marathon	69.845 km	22
18.06	6d	4th Six Days in the Dome - The Redux	552.545 km	9
08.05	24h	1st Island Time 24 Hour Race	99.779 km	20
27.03	24h	2nd Vernal Equinox 24 Hour Race	64.373 km	28
2020
17.11	6d	8th Icarus Florida 6 Day UltraFest	403.221 km	7
17.10	24h	3rd Bear Lake Ultra Race	59.867 km	47
10.07	24h	1st 24 Hour Summer Stampede 24 Hour Ultra Race	102.998 km	4
14.02	48h	7th Jackpot Ultra Running Festival 48 Hour Race	198.753 km	11
2019
18.11	6d	7th Icarus Florida 6 Day UltraFest	529.796 km	2 🥈
19.10	Backyard Ultra	8th Big Dog's Backyard Ultra	60.354 km (9h)	69
28.09	24h	2nd Bear Lake Ultra Race	84.812 km	34
21.09	24h	13th North Coast 24 Hour Endurance Run	151.460 km	7
25.08	6d	2nd Six Days in the Dome - The Redux	599.551 km	22
25.08	72h	2nd Six Days in the Dome - The Redux - 72h Split	286.912 km	28
08.06	50km	Two Parks Trail Run	7:10:07 h	20
01.06	52.4mi	9th Yankee Springs 52 Mile Trail Run	13:09:24 h	17
11.05	24h	24th Dawn to Dusk to Dawn 24 Hour	115.200 km	28
26.04	6d	22nd Sri Chinmoy 6 Day Race	410.704 km	30
26.04	24h	22nd Sri Chinmoy 6 Day Race - 24h Split	110.722 km	14
26.04	48h	22nd Sri Chinmoy 6 Day Race - 48h Split	207.283 km	13
2018
28.12	6d	34th Across the Years, 6 days	341.277 km	40
12.11	6d	6th Icarus Florida 6 Day UltraFest	355.938 km	8
22.09	24h	12th North Coast 24 Hour Endurance Run	80.926 km	99
2017
27.12	6d	33rd Across the Years, 6 days	483.197 km	16
28.10	12h	7th Bad Apple Ultra - 12 hour	90.123 km	13
30.09	50km	2nd Thru The Leaves 50k Trail Run	7:00:56 h	15
16.09	24h	11th North Coast 24 Hour Endurance Run	126.549 km	49
29.07	12h	2nd Loopty Loop 12 Hour Ultra Trail Marathon	81.110 km	29
21.04	6d	20th Sri Chinmoy 6 Day Race	424.866 km	24
21.04	24h	20th Sri Chinmoy 6 Day Race - 24h Split	93.341 km	25
21.04	48h	20th Sri Chinmoy 6 Day Race - 48h Split	154.497 km	29
2016
14.11	6d	4th Icarus Florida 6 Day UltraFest	544.485 km	4
17.09	24h	10th North Coast 24 Hour Endurance Run	120.314 km	75
23.07	24h	3rd Montour 24 Endurance Runs - 24hrs run	74.834 km	59
24.04	50km	5th The Trail Marathon 50K	6:10:10 h	54
02.04	50mi	22nd Umstead Endurance Run 50 Miles	11:48:35 h	38
2015
28.12	6d	31st Across the Years, 6 days	520.365 km	12
16.11	6d	3rd Icarus Florida 6 Day UltraFest - Fall Edition	550.921 km	8
24.10	100mi	3rd Kansas Rails-to-Trails Fall Extravaganza 100 Mile	26:04:15 h	23
19.09	24h	9th North Coast 24 Hour Endurance Run	133.444 km	51
25.07	50mi	9th Burning River 50 Mile Endurance Run	13:34:00 h	122
20.06	50km	23rd Niagara Ultra 50 km	6:03:54 h	121
23.04	6d	18th Sri Chinmoy 6 Day Race	643.737 km	3 🥉
23.04	24h	18th Sri Chinmoy 6 Day Race - 24h Split	114.263 km	15
23.04	48h	18th Sri Chinmoy 6 Day Race - 48h Split	209.214 km	9
14.02	100mi	2nd Jackpot Ultra Running Festival 100 Mile Race	28:47:34 h	51
2014
13.12	100mi	1st Brazos Bend 100 - 100 Mile	28:08:38 h	52
06.12	50km	2nd Caloosahatchee Ultra Run	7:07:59 h	25
15.11	100mi	1st Tunnel Hill 100 Mile Race	21:26:44 h	20
20.09	24h	8th North Coast 24 Hour Endurance Run	81.257 km	114
20.09	12h	8th North Coast 24 Hour Endurance Run - 12h Split	81.258 km	54
04.08	6d	1st Six Days in the Dome	503.354 km	17
04.08	24h	1st Six Days in the Dome - 24h Split	129.455 km	22
04.08	48h	1st Six Days in the Dome - 48h Split	212.996 km	17
18.07	24h	1st Christmas in July 24 Hour Run	100.246 km	26
15.02	12h	1st Jackpot Ultra Running Festival 12 Hour Race	68.976 km	23
2013
26.10	12h	3rd Bad Apple Ultra - 12 hour	96.560 km	8
21.09	24h	7th North Coast 24 Hour Endurance Run	166.065 km	13
15.06	50km	2nd Corner Canyon Ultra Trail Run	8:15:23 h	29
09.02	100mi	8th Iron Horse 100 Mile Endurance Run	23:29:17 h	19
2012
29.12	50km	16th Huff 50K Trail Run	5:10:05 h	57
27.10	100km	10th Javelina Jundred 100 km Endurance Run	18:48:45 h	135
13.10	100km	2nd Top of Michigan (TOM) 100k Ultra	12:19:25 h	18
22.09	24h	5th North Coast 24 Hour Endurance Run	133.627 km	26
03.05	72h	4th Peak Ultra 30/50/100/150/200 Endurance Runs	193.121 km	7
29.04	50km	1st The Trail Marathon 50K	5:56:11 h	77
31.03	50mi	18th Umstead Endurance Run 50 Miles	11:47:41 h	50
2011
12.11	100km	9th Javelina Jundred 100 km Endurance Run	14:24:12 h	42
10.09	100km	3rd Run Woodstock - 100 km Hallucination Run	13:28:36 h	5
02.04	50mi	17th Umstead Endurance Run 50 Miles	10:48:11 h	37
05.02	100mi	19th Rocky Raccoon 100 Mile Trail Runs	21:00:23 h	33
2010
06.11	50mi	28th Mountain Masochist 50 Mile Trail Run	10:16:00 h	90
24.09	100mi	12th The Bear 100 Mile Endurance Run	33:19:00 h	91
11.09	50km	8th Dances with Dirt - Hell 50K Ultra	5:06:39 h	14
31.07	100mi	4th Burning River 100 Mile Endurance Run	26:12:24 h	85
10.07	50mi	7th Dances with Dirt - Devil's Lake 50M Ultra	10:43:44 h	17
15.05	50mi	7th Dances with Dirt - Gnaw Bone 50 Mile Ultra	10:54:44 h	15
06.02	100mi	18th Rocky Raccoon 100 Mile Trail Run	25:27:32 h	103
2009
07.11	50mi	27th Mountain Masochist 50 Mile Trail Run	10:57:03 h	123
19.09	50mi	10th North Country Trail Run 50 Mile	8:33:36 h	14
12.09	50mi	7th Dances with Dirt - Hell 50M Ultra	11:18:13 h	25
11.07	50mi	6th Dances with Dirt - Devil's Lake 50M Ultra	10:19:57 h	17
20.06	50km	17th Niagara Ultra 50 km	4:41:28 h	30
09.05	50mi	6th Dances with Dirt - Gnaw Bone 50 Mile Ultra	11:47:14 h	17
07.02	50mi	6th Dances with Dirt - Green Swamp 50 Mile Ultra	11:05:08 h	9
2008
06.09	50km	6th Dances with Dirt - Hell 50K Ultra	6:10:06 h	42

Filter

Runner	Races in common

DUV-index calculation details

#	Date	Race	Credited km	DUV-index+
✓ 1	21/4/2023	25th Sri Chinmoy 6 Day Race	651,22	×6
✓ 2	23/4/2015	18th Sri Chinmoy 6 Day Race	643,74	×6
✓ 3	25/8/2019	2nd Six Days in the Dome - The Redux	599,55	×5
✓ 4	16/6/2023	6th Six Days in the Dome - The Redux	591,57	×5
✓ 5	28/12/2021	37th Across the Years, 6 days	563,19	×5
✓ 6	18/6/2021	4th Six Days in the Dome - The Redux	552,55	×5
✓ 7	16/11/2015	3rd Icarus Florida 6 Day UltraFest - Fall Edition	550,92	×5
✓ 8	14/11/2016	4th Icarus Florida 6 Day UltraFest	544,49	×5
✓ 9	18/11/2019	7th Icarus Florida 6 Day UltraFest	529,80	×5
✓ 10	28/12/2015	31st Across the Years, 6 days	520,37	×4
✓ 11	4/8/2014	1st Six Days in the Dome	503,35	×4
✓ 12	27/12/2017	33rd Across the Years, 6 days	483,20	×4
✓ 13	21/4/2017	20th Sri Chinmoy 6 Day Race	424,87	×4
✓ 14	26/4/2019	22nd Sri Chinmoy 6 Day Race	410,70	×3
✓ 15	17/11/2020	8th Icarus Florida 6 Day UltraFest	403,22	×3
✓ 16	12/11/2018	6th Icarus Florida 6 Day UltraFest	355,94	×3
✓ 17	28/12/2022	38th Across the Years, 6 days	342,30	×3
✓ 18	28/12/2018	34th Across the Years, 6 days	341,28	×3
✓ 19	18/2/2022	9th Jackpot Ultra Running Festival 72 Hour Race	273,59	×2
✓ 20	14/2/2020	7th Jackpot Ultra Running Festival 48 Hour Race	198,75	×1
✓ 21	3/5/2012	4th Peak Ultra 30/50/100/150/200 Endurance Runs	193,12	×1
✓ 22	3/3/2023	10th Jackpot Ultra Running Festival 48 Hour Race	178,42	×1
✓ 23	21/9/2013	7th North Coast 24 Hour Endurance Run	166,07	×1
✓ 24	13/11/2021	5th The Stinger 24 Hour Race	162,56	×1
✓ 25	19/6/2022	5th Six Days in the Dome - The Redux	160,97	×1
✓ 26	24/10/2015	3rd Kansas Rails-to-Trails Fall Extravaganza 100 Mile	160,93	×1
✓ 27	14/2/2015	2nd Jackpot Ultra Running Festival 100 Mile Race	160,93	×1
✓ 28	13/12/2014	1st Brazos Bend 100 - 100 Mile	160,93	×1
✓ 29	15/11/2014	1st Tunnel Hill 100 Mile Race	160,93	×1
✓ 30	9/2/2013	8th Iron Horse 100 Mile Endurance Run	160,93	×1
✓ 31	5/2/2011	19th Rocky Raccoon 100 Mile Trail Runs	160,93	×1
✓ 32	24/9/2010	12th The Bear 100 Mile Endurance Run	160,93	×1
✓ 33	31/7/2010	4th Burning River 100 Mile Endurance Run	160,93	×1
✓ 34	6/2/2010	18th Rocky Raccoon 100 Mile Trail Run	160,93	×1
✓ 35	21/9/2019	13th North Coast 24 Hour Endurance Run	151,46	×1
✓ 36	22/9/2012	5th North Coast 24 Hour Endurance Run	133,63	×1
✓ 37	19/9/2015	9th North Coast 24 Hour Endurance Run	133,44	×1
✓ 38	7/5/2022	27th Dawn to Dusk to Dawn 24 Hour	130,80	×1
✓ 39	11/11/2023	7th The Stinger 24 Hour Race	127,49	×1
✓ 40	16/9/2017	11th North Coast 24 Hour Endurance Run	126,55	×1
✓ 41	12/11/2022	6th The Stinger 24 Hour Race	125,11	×1
✓ 42	17/9/2016	10th North Coast 24 Hour Endurance Run	120,31	×1
✓ 43	11/5/2019	24th Dawn to Dusk to Dawn 24 Hour	115,20	×1
✓ 44	7/10/2023	6th Bear Lake Ultra Race	114,75	×1
✓ 45	10/7/2020	1st 24 Hour Summer Stampede 24 Hour Ultra Race	103,00	—
✓ 46	17/5/2025	4th Perfect PR Backyard	100,59	—
✓ 47	18/7/2014	1st Christmas in July 24 Hour Run	100,25	—
✓ 48	27/10/2012	10th Javelina Jundred 100 km Endurance Run	100,00	—
✓ 49	13/10/2012	2nd Top of Michigan (TOM) 100k Ultra	100,00	—
✓ 50	12/11/2011	9th Javelina Jundred 100 km Endurance Run	100,00	—
✓ 51	10/9/2011	3rd Run Woodstock - 100 km Hallucination Run	100,00	—
✓ 52	8/5/2021	1st Island Time 24 Hour Race	99,78	—
✓ 53	26/10/2013	3rd Bad Apple Ultra - 12 hour	96,56	—
✓ 54	1/4/2022	3rd Vernal Equinox 12 Hour Race	93,34	—
✓ 55	28/10/2017	7th Bad Apple Ultra - 12 hour	90,12	—
✓ 56	13/5/2023	28th Dawn to Dusk to Dawn 24 Hour	85,60	—
✓ 57	8/10/2022	5th Bear Lake Ultra Race	84,81	—
✓ 58	9/10/2021	4th Bear Lake Ultra Race	84,81	—
✓ 59	28/9/2019	2nd Bear Lake Ultra Race	84,81	—
✓ 60	1/6/2019	9th Yankee Springs 52 Mile Trail Run	84,33	—
✓ 61	20/9/2014	8th North Coast 24 Hour Endurance Run	81,26	—
✓ 62	29/7/2017	2nd Loopty Loop 12 Hour Ultra Trail Marathon	81,11	—
✓ 63	22/9/2018	12th North Coast 24 Hour Endurance Run	80,93	—
✓ 64	16/9/2023	17th Run Rabbit Run 50 Mile Endurance Run	80,47	—
✓ 65	17/9/2022	16th Run Rabbit Run 50 Mile Endurance Run	80,47	—
✓ 66	2/4/2016	22nd Umstead Endurance Run 50 Miles	80,47	—
✓ 67	25/7/2015	9th Burning River 50 Mile Endurance Run	80,47	—
✓ 68	31/3/2012	18th Umstead Endurance Run 50 Miles	80,47	—
✓ 69	2/4/2011	17th Umstead Endurance Run 50 Miles	80,47	—
✓ 70	6/11/2010	28th Mountain Masochist 50 Mile Trail Run	80,47	—
✓ 71	10/7/2010	7th Dances with Dirt - Devil's Lake 50M Ultra	80,47	—
✓ 72	15/5/2010	7th Dances with Dirt - Gnaw Bone 50 Mile Ultra	80,47	—
✓ 73	7/11/2009	27th Mountain Masochist 50 Mile Trail Run	80,47	—
✓ 74	19/9/2009	10th North Country Trail Run 50 Mile	80,47	—
✓ 75	12/9/2009	7th Dances with Dirt - Hell 50M Ultra	80,47	—
✓ 76	11/7/2009	6th Dances with Dirt - Devil's Lake 50M Ultra	80,47	—
✓ 77	9/5/2009	6th Dances with Dirt - Gnaw Bone 50 Mile Ultra	80,47	—
✓ 78	7/2/2009	6th Dances with Dirt - Green Swamp 50 Mile Ultra	80,47	—
✓ 79	4/10/2025	8th Bear Lake Ultra Race	79,82	—
80	23/7/2016	3rd Montour 24 Endurance Runs - 24hrs run	74,83	—
81	24/7/2021	6th Loopty Loop 12 Hour Ultra Trail Marathon	69,85	—
82	15/2/2014	1st Jackpot Ultra Running Festival 12 Hour Race	68,98	—
83	21/5/2022	1st Perfect PR Backyard	67,06	—
84	27/3/2021	2nd Vernal Equinox 24 Hour Race	64,37	—
85	19/10/2019	8th Big Dog's Backyard Ultra	60,35	—
86	17/10/2020	3rd Bear Lake Ultra Race	59,87	—
87	6/6/2025	5th Island Time 24 Hour Race	54,72	—
88	1/4/2023	17th Kal-Haven Trail Run	53,91	—
89	22/7/2023	5th Ode to Laz Backyard Ultra	53,65	—
90	20/5/2023	2nd Perfect PR Backyard	53,65	—
91	30/7/2023	4th Kensington Marathon 50km Race	50,00	—
92	8/6/2019	Two Parks Trail Run	50,00	—
93	30/9/2017	2nd Thru The Leaves 50k Trail Run	50,00	—
94	24/4/2016	5th The Trail Marathon 50K	50,00	—
95	20/6/2015	23rd Niagara Ultra 50 km	50,00	—
96	6/12/2014	2nd Caloosahatchee Ultra Run	50,00	—
97	15/6/2013	2nd Corner Canyon Ultra Trail Run	50,00	—
98	29/12/2012	16th Huff 50K Trail Run	50,00	—
99	29/4/2012	1st The Trail Marathon 50K	50,00	—
100	11/9/2010	8th Dances with Dirt - Hell 50K Ultra	50,00	—
101	20/6/2009	17th Niagara Ultra 50 km	50,00	—
102	6/9/2008	6th Dances with Dirt - Hell 50K Ultra	50,00	—
103	5/10/2024	7th Bear Lake Ultra Race	49,89	—