One of Hawaii's most divisive issues is centered on a largely barren, wintry mountain.

The $1.4 billion Thirty Meter Telescope project on Thursday won key state approval to join other telescopes atop Mauna Kea. But passionate protesters vow not to stop fighting construction on land that's sacred to Native Hawaiians.

Their willingness to endure frigid nights camped on the mountain and to be arrested proved successful in blocking construction in the past.

Scientists say the telescope will lead to important discoveries.

Land board chairwoman Suzanne Case says the 5-2 decision to grant a construction permit was one of the toughest choices for the board.

Opponents will likely appeal.

The project had to seek a permit again after the state Supreme Court invalidated one the board granted previously.