Pacific to Tasman: The Great Alpine Highway, Ocean to Ocean

SH73 is New Zealand's classic coast-to-coast crossing, and this version drives it the honest way: from the Pacific surf at Christchurch's New Brighton Pier, across the checkerboard Canterbury Plains, over the spine of the Southern Alps, and down to the rainforest and driftwood of the Tasman shore at Kumara Beach, ocean to ocean in an afternoon. The famous Coast to Coast multisport race has crossed the island along this very corridor since 1983, which makes the drive's bookend ritual official: touch the sea at both ends. The route was punched through in astonishing haste in the 1860s, after surveyor Arthur Dobson found the pass that bears his name and gold fever on the West Coast demanded a road; the crossing has been a test of engineering ever since, culminating in the 440-meter Otira Viaduct of 1999, which appears to float across a gorge too unstable for a conventional road. In between come wonders in quick succession: the sacred limestone tor field of Kura Tāwhiti at Castle Hill, a walk-through cave for the adventurous, the braided silver sprawl of the Waimakariri River, and Arthur's Pass National Park itself, the South Island's oldest, whose village sits beneath a 131-meter waterfall and whose resident keas treat the viaduct lookout as their personal clubhouse. The famous quirk of the drive is that its namesake pass, at 920 meters, is not even its highest point; Porters Pass, crossed barely an hour from the city, tops it by about twenty meters. The TranzAlpine railway shadows the road the whole way, so one of the world's great train journeys runs alongside one of its great drives.

Key Stops

New Brighton Pier and the plains run. Begin at the Pacific: Christchurch's long concrete pier reaches out over the surf at New Brighton, the city's beach suburb, and a walk to its end (coffee from the library complex at its base in hand) is the proper first act of a coast-to-coast crossing. Touch the water, then drive west through the Garden City and out onto SH73, dead straight across the Canterbury Plains, with the Alps rising ahead like a wall and, on the right day, the great smooth arc of nor'west cloud above them. Watch the mountains grow for an hour.

Springfield. The last plains town, marked by its improbable giant pink doughnut (a 2007 film promotion the town simply kept). Fuel up and grab coffee: this is the reliable last stop before the mountains.

Porters Pass and Lake Lyndon. The highway's first climb crests at roughly 940 meters, the route's true high point, before dropping past little Lake Lyndon into a wide tussock basin ringed by scree-streaked ranges. In winter this is often the icier pass of the two.

Castle Hill / Kura Tāwhiti. A hillside strewn with colossal limestone tors, sculpted smooth and scattered as if by giants: a 1.4 km track wanders among them. The site is sacred to Ngāi Tahu, a world-famous bouldering ground, and the surrounding high country stood in for Narnia's battlefields on film. Treat it as the cultural site it is and stay on the tracks.

Cave Stream / Broken River. For the well-prepared, a 594-meter limestone cave walk-through: cold water, full darkness, and a torch each, emerging upstream half an hour later grinning. Only in low water and settled weather; the stream rises fast after rain.

The Craigieburn lakes and forest. Kettle lakes (Lake Pearson the loveliest) mirror the ranges beside the road, mountain beech forest closes in, and gravel side roads climb to the Craigieburn club ski fields. Quiet picnic country between the drama.

Bealey and the Waimakariri. The road meets the Waimakariri where the river sprawls across its gravel bed in braided silver threads, one of the great sights of the crossing, with the historic Bealey Hotel perched above. The valley funnels you straight toward the park.

Arthur's Pass village. New Zealand's highest-altitude village in the heart of the South Island's oldest national park: a DOC visitor centre with the crossing's whole story, mountain cafes, and the essential walk to Devil's Punchbowl Falls, a 131-meter cascade reached by a steep, step-heavy hour return. The fit and experienced tackle Avalanche Peak; everyone else photographs it.

The summit and Dobson Memorial. At 920 meters the road crests the pass proper, marked by the memorial to Arthur Dobson and surrounded by alpine wetlands where the short Dobson Nature Walk samples the tops in twenty minutes. The vegetation flips from dry eastern beech to dripping western rainforest almost at the obelisk.

The Otira Viaduct and gorge. The descent's showpiece: from the lookout, the 440-meter viaduct seems to hover across the unstable gorge it conquered in 1999, with a rock shelter shielding the road beyond. This lookout is the keas' headquarters, and in December and January the gorge walls burn crimson with flowering southern rata. Tiny Otira below grew around the 1923 rail tunnel, a marvel of its day, and keeps an endearingly eccentric hotel.

Lake Brunner / Moana (detour). At Jacksons, a side road runs to the West Coast's largest lake, all mirror water, white herons, and legendary trout fishing, with the TranzAlpine calling at its village. A worthy hour if the day allows.

Kumara and Kumara Beach. The highway emerges through regenerating forest at Kumara, an 1870s gold town charmingly revived around its Theatre Royal Hotel. Don't stop at the junction: carry on the last few minutes to Kumara Beach, the wild, driftwood-strewn Tasman shore where the Coast to Coast race traditionally begins, and finish the crossing the way it deserves, with the second ocean on your boots.

Driving Tips

Treat winter crossings seriously. Snow and ice close or restrict SH73 several times each winter, chains must be carried when signposted, and Porters Pass often ices before Arthur's itself. Check the NZTA status before leaving Christchurch or the coast between June and October.

Gear down for the Otira Gorge. The western descent is genuinely steep with tight curves and heavy freight traffic sharing the road; use low gear rather than brakes, let trucks and locals past at the slow-vehicle bays, and keep patience at the rock shelter's narrow line.

Obey kea law. The viaduct lookout and village car parks belong to the alpine parrots: never feed them (it harms them and emboldens them), close windows, and don't leave wipers, seals, or antennas unattended. They are endangered, brilliant, and faster than you.

Plan for two climates in one day. The nor'wester can mean violent gusts on the plains (high-sided vehicles beware), sun in the east, and torrential rain in the west, all simultaneously. Check both coasts' forecasts; rain turns the western waterfalls magnificent.

Do Devil's Punchbowl, budget for the steps. It is the crossing's essential short walk: an hour return, much of it stairs, to the base of the full 131-meter drop. Bring a rain shell for the spray.

Enter Cave Stream prepared or not at all. Torches for every person, warm layers, low water, and settled weather are non-negotiable; the cave has claimed the unprepared. When conditions are right, it's one of New Zealand's best free adventures.

Leave Avalanche Peak to the equipped. It's a serious alpine day climb with real exposure and fast-changing weather; register intentions and check conditions at the DOC visitor centre, or enjoy it from the valley.

Expect one-lane bridges and sandflies west of the divide. Both arrive as soon as the rainforest does; give-way arrows govern the bridges, and repellent belongs in the door pocket.

Ride the rails one way if you can. The TranzAlpine parallels the entire drive and ranks among the world's great train journeys; some travelers train over and drive back (rental logistics permitting), and everyone should at least watch it cross the Waimakariri bridges.

Time the rata if you can. In good flowering years, December and January set the Otira gorge walls ablaze with crimson southern rata, the crossing at its most photogenic.

Honor both oceans. The race that named this crossing runs beach to beach, and so should the drive: a hand in the Pacific at New Brighton, a hand in the Tasman at Kumara Beach. From there, Kumara Junction hands you to Hokitika and the glacier road south, linking this drive to your Haast Pass route and completing the full South Island loop, with Punakaiki's Pancake Rocks an hour north as the bonus track.

For more information visit: DOC: Arthur's Pass National Park