The Kaimai Range ( sometimes referred to as the Kaimai Ranges) is a mountain range in the North Island of New Zealand. It is part of a series of ranges, with the Coromandel Range to the north and the Mamaku Ranges to the south. The Kaimai Range separates the Waikato in the west from the Bay of Plenty in the east.
The highest point of the range is Mount Te Aroha (952 m), at the foot of which is the town of Te Aroha. The range's terrain is rough, and only two roads pass over it: State Highway 2, across the northern end of the range through Karangahake Gorge, and New Zealand State Highway 29 from Tauranga to Hamilton.
Within the Kaimai Ranges the Hendersons Tramline loop track follows the route of bush tramlines and haul lines once used to extract logs from the bush. The walk includes forest and clearings near the fringe of the park. A side track off the main walk leads down to the base of a waterfall and a large swimming hole.
The Kaimai Range is the result of a fault that uplifted primarily andesitic rocks from long-extinct volcanoes. This fault has not been active for about 140,000 years and started more than a million years ago.
The Kaimai Railway Tunnel runs for nearly nine kilometres under the range, making it the longest tunnel in New Zealand. Construction of the tunnel started from both sides of the range in 1969: the headings met in 1976 and the tunnel opened on 12 September 1978. The Kaimai Range and this tunnel led to a Silver Fern railcar service between Auckland and Tauranga being named the Kaimai Express. This service operated from 1991 until 2001.
Flight 441 disaster
At approximately 9:09 am on 3 July 1963 the DC-3 Skyliner ZK-AYZ Hastings operating New Zealand National Airways Corporation Flight 441 from Whenuapai Airport, Auckland to Tauranga crashed into the range. All 23 aboard died, making it the worst air disaster in mainland New Zealand.
The New Zealand Post Office engineering division (radio) built and maintained a microwave communications facility near the top of Kaimai range, close to the Hamilton–Tauranga highway saddle. In the 1960s it was a Lenkurt relay as part of the national network, linking Sanitorium Hill near Cambridge to Rotorua, with a spur to Tauranga. It now has cell phone and various other radio communications facilities, and is owned and operated by Telecom New Zealand. Land Parcel: Part Section 126 Block II Tapapa SD 
Airways New Zealand maintains a Secondary Surveillance Radar installation on Te Weraiti, a peak on the Kaimai range, 5 kilometers north of the State Highway 29 saddle. This is used to facilitate air traffic control of transponder equipped aircraft in the area.