Old Mamalahoa Highway

Old Mamalahoa Highway, Big Island

The Old Mamalahoa Highway on the Big Island's Hamakua Coast is a narrow and winding coastline road that begins about 5 miles (8 km) north of Hilo. The 4-mile (6.4 km) stretch until the Hawaii Tropical Botanical Garden are breathtaking. The vegetation is very lush and there is a great lookout point along the way, right before you reach the botanical garden. It overlooks Onomea Bay and the surrounding rainforest.

Key Features

Rainforest drive: Lush 4-mile scenic section north of Hilo

Coastal setting: Views toward Onomea Bay and the Hamakua Coast

Garden access: Leads to Hawaii Tropical Botanical Garden

Road character: Narrow, winding and shaded with old coastal-road charm

Nearby towns: Close to Papaikou, Pepeekeo and Hilo

Best for: Short scenic detour, garden visits, photography and coast views

Visitor note: Watch for wet pavement, local traffic and limited pullouts

Frequently Asked Questions

Where is Old Mamalahoa Highway?

Old Mamalahoa Highway is on the Big Island's Hamakua Coast north of Hilo, near Papaikou, Onomea Bay and the Hawaii Tropical Botanical Garden area.

How long is the Old Mamalahoa Highway scenic drive?

The best-known scenic section is about 4 miles long. It winds through lush rainforest, narrow curves, bridges and coastal viewpoints near Onomea Bay.

What is Old Mamalahoa Highway known for?

The road is known for tropical greenery, ocean views, Onomea Bay, rainforest scenery, historic road character and access to Hawaii Tropical Botanical Garden.

Is Old Mamalahoa Highway difficult to drive?

It is paved and short, but it is narrow and winding. Drive slowly, watch for local traffic, wet pavement, pedestrians, garden visitors and cars entering small driveways.

What should visitors check before going?

Check current garden hours, weather and roadwork before driving. Rain can make the road slick, and nearby Highway 19 work may affect travel times.