Is there loose volcanic ash on Mt. Rinjani?

Yes, loose volcanic ash and scree are defining features of the Rinjani trekking experience, and they’re present in large quantities on the upper slopes and especially along the summit route. Unlike compacted soil or solid rock, this material consists of fine volcanic gravel, ash, and sand-sized particles that shift underfoot with every step. It’s like climbing a steep sand dune made of sharp rocks.

During the summit push, climbing over two thousand meters of this terrain, you’ll take two steps forward and slide one step back. It’s physically exhausting and mentally frustrating if you’re not expecting it. The ash also kicks up when wind blows or larger groups move through ahead of you, so a neck gaiter or buff can help reduce dust inhalation. You’ll taste the volcano by the end.

At Lombok-Indonesia.org, guides brief trekkers on exactly what to expect from the scree sections and recommend hiking boots with deep tread and trekking poles for better purchase on the unstable surface. The ash isn’t dangerous in itself, but it transforms the hike from a simple walk into a genuine mountaineering challenge that demands patience, balance, and proper footwear.

Descending through loose ash is equally demanding on the knees, which is why poles are so highly recommended for the return journey. Once you’ve experienced that slide-back sensation, you’ll understand why everyone talks about it. It’s uniquely Rinjani.