Northburn100
Northburn 100 Mile
Cromwell (Northburn Station)
Race guide
Updated 29 June 2026
The Northburn 100 Mile is one of New Zealand's most demanding ultra-marathons, covering 161 km with 8495 m of elevation gain on the raw, exposed terrain of Northburn Station above Cromwell in Central Otago. The course climbs to a high point of 1664 m and drops back to base (around 230 m) not once but three times, making it a relentless test of physical and mental endurance rather than a point-to-point journey. Starting and finishing at the base marquee, the race is structured as three distinct loops — each sending you back into the mountains before returning to a crew-accessible base — which shapes every decision you make around pacing, nutrition, and gear management. The landscape is quintessentially Central Otago: tussock-covered ridgelines, steep schist-strewn slopes, exposed alpine terrain with minimal shelter, and dramatic elevation change baked into every loop. There is nowhere flat to recover. If you are targeting a finish before the Day 6 06:00 cut-off at the 161.4 km base marquee, you need a clear strategy from the gun — this race rewards patience and punishes early ambition.
Course & Terrain Overview
The course is divided into three loops, all beginning and ending at the base marquee (approximately 230–246 m elevation). Loop 1 runs for 50 km with a mid-loop aid station at 25 km sitting at a striking 1642 m — meaning you gain roughly 1400 m of vertical in the first half of that loop alone. Loop 2 extends from 50 km to 110 km (60 km in length), with the TW Aid Station at 75 km perched at 1366 m. Loop 3 runs from 110 km to the 161.4 km finish, with the TW Aid Station appearing again at 135 km at 1488 m. Each loop returns you to near sea-level before launching you back into the mountains, so the cumulative 8495 m of climbing is spread across three distinct ascent-descent cycles rather than a single progressive profile. The terrain underfoot is technical throughout — expect rough tussock, loose schist, unmarked high-country tracks, and ridgelines that offer little protection from wind. Below the 600 m mark, dry Central Otago conditions can make the lower slopes dusty and hard-packed; above 1000 m, the ground becomes more broken and the footing demands concentration, particularly on descents. Poles are strongly worth considering: the repeated steep climbs will tax your quads and the long descents late in the race will destroy them without support.
Decisive Climbs and Where the Race Is Won or Lost
The Loop 1 mid-point aid station at 1642 m is the highest point you will visit and it arrives at just 25 km — deceptively early. Runners who chase the climb out of the base marquee typically pay for it on the long descent back down and even more so on the re-ascent in Loops 2 and 3. The real race begins at the 110 km base checkpoint: you have already covered two full mountain loops, your legs have absorbed the bulk of the 8495 m of gain, and you now face a third push up to 1488 m at the 135 km TW Aid Station before the final descent to the finish. The section between 110 km and 135 km — ascending from 235 m back to 1488 m — is where many races unravel. By this point sleep deprivation, glycogen depletion, and cumulative quad damage all converge. Runners who have managed effort carefully through Loops 1 and 2 and arrived at the 110 km checkpoint in reasonable condition can still run the final loop. Those who have redlined earlier will be reduced to a slow grind. The descent from 1488 m to the finish line (approximately 26 km from the TW aid station to the 161.4 km marquee) is long enough to feel punishing on destroyed legs but manageable if you have preserved eccentric quad strength through the earlier loops.
Pacing Strategy
A three-loop structure with crew access at the base (50 km, 110 km, and finish) demands a conservative early pacing strategy. Treat Loop 1 as pure investment: hike the climbs, run only where the terrain genuinely invites it, and arrive at the 50 km base checkpoint feeling well within yourself. The 25 km mid-loop aid station at 1642 m has no crew access, so you must carry sufficient supplies from base to get there and back — roughly 25 km of mountain terrain each way. For Loop 2, the TW Aid Station at 75 km (1366 m) offers a resupply point mid-loop, but again no crew. The 35 km leg from base to TW station and the 35 km leg from TW station back to base at 110 km should be approached as two separate efforts. Aim to reach the 110 km base checkpoint with enough time to change gear, eat a proper meal, rest briefly if conditions allow, and still have a realistic buffer against the Day 6 06:00 cut-off. On Loop 3, the priority shifts: there is now a hard finish cut-off to respect, and you should know your pace per kilometre on the ascent and plan accordingly. Walk every climb, protect the quads on every descent, and keep moving.
Fuelling and Aid Station Strategy
With only two mid-loop mountain aid stations across three loops — the Loop 1 station at 25 km/1642 m, and the TW Aid Station used in both Loop 2 (75 km/1366 m) and Loop 3 (135 km/1488 m) — and three base crew points at 50 km, 110 km, and the finish, your fuelling plan must account for long stretches between resupply on the mountain. The leg from base to the Loop 1 mid-point alone covers 25 km of high-country terrain; carry at least 4–6 hours of calories and adequate water for the conditions. At the base crew points, prioritise real food alongside race nutrition — your crew can bring hot food, dry clothes, and replacement gear. The 110 km base stop is the most important: use it deliberately. Eat a substantial meal, address any hot spots or blisters, swap shoes if needed, and mentally reset before Loop 3. Hydration needs vary significantly with Central Otago's climate — the lower slopes can be hot and dry while the ridgelines above 1400 m can be cold and windy. Carry a mandatory layer for the high ground regardless of conditions at base, and adjust your electrolyte intake to match the effort and temperature at each stage of the loop.
Conditions to Expect
Northburn Station sits in the rain shadow of the Southern Alps, giving Central Otago one of New Zealand's most continental climates: hot, dry, and sunny at lower elevations, but rapidly changing and exposed above 1000 m. Depending on the time of year the race is held, daytime temperatures on the lower slopes can be genuinely warm while the ridgeline at 1642 m can be cold, windy, and — in poor conditions — disorienting. The combination of UV exposure on the open tussock and cold at altitude means layering and sun protection are both non-negotiable. Night running is inevitable at this distance: 161 km with 8495 m of climbing means most field athletes will be out for well over 24 hours, with some runners navigating the back half of the course through multiple nights. The mountain terrain becomes significantly more technical in the dark, and the psychological weight of returning to the mountain on Loop 3 after two nights of effort is considerable. Train for back-to-back long days, practice night navigation, and do not underestimate the cold at altitude after dark — even in summer, wind on the high ridgelines at 1488–1642 m will cut through inadequate layers quickly.
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Checkpoints & cut-offs
⚠ Auto-researched from public sources — aid stations and cut-offs may be incomplete. Confirm against the official roadbook before race day.
0 km · 230 m · —
15 km · 928 m · —
25 km · 1642 m · —
48.4 km · 234 m · —
62 km · 1291 m · —
82 km · 789 m · —
98 km · 354 m · —
110 km · 235 m · —
120 km · 1201 m · —
127 km · 862 m · —
140 km · 1370 m · —
148 km · 694 m · —
154 km · 676 m · —
161.4 km · 226 m · Mon 06:00
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Course data researched from public sources — verify against the official roadbook.