Emergency services took almost 90 minutes to reach the scene of a fatal crash near Turangi on Sunday.
Bay of Plenty road policing manager Inspector Kevin Taylor said all emergency services had difficulty with access to the remote location on a private forestry road and had to rely on a local on a trailbike to guide them through.
A 14-year-old boy was killed and two others - a 16-year-old boy and a 15-year-old girl - received minor injuries in the crash, which happened around 12.25pm on Waimarino Rd.
Mr Taylor said the serious crash unit was investigating the crash, which happened in an area surrounded by pine trees.
"It seems the vehicle has gone up a bank and hit a tree," Mr Taylor said.
"The vehicle has rolled over and the driver has been thrown from the vehicle. All three were out of the vehicle when emergency services arrived. It's not a road open to the public, generally speaking. They would have had a key or gone through a ford in a river. Emergency services had great difficulty finding the scene and it took between an hour and an hour and a half to get there."
He said one route in involved a river crossing but that was not suitable for the ambulance or police cars to use.
Mr Taylor said it was unclear whether the driver had been wearing a seatbelt, as violent rollovers can cause belts to snap or for bolts to rip out, and that would be one focus of the investigation.