Mod Sun says he’ll spend the rest of his life thinking about Sahara Ray … and he’s opening up about the deeply personal ways he’s honoring his late ex.

TMZ caught up with the musician at LAX on Friday, just weeks after Sahara’s tragic death … and he told us he’s been retracing their footsteps on a California road trip, revisiting places where they made memories together … including Big Sur, where they once slept on the beach.

“I’ll think about that girl for the rest of my life,” he told us … calling her a “one of one” who left a lasting impression on everyone she met.

But that’s not the only way he’s keeping her memory alive … Mod revealed he recently released a song completely inspired by Sahara, though he stopped short of naming the track, leaving fans to connect the dots.

Mod also praised Sahara’s family and the way they’ve celebrated her life … speaking about the beauty of surfers’ traditional paddle-out tributes, though he was careful not to share details he felt should come directly from her family.

He said the outpouring of love following her death speaks volumes about the kind of person she was … with so many people remembering her the same beautiful way.