Böshorn, Mountain summit in Valais, Switzerland.

Böshorn, also called Rauthorn, is a 3,268-metre mountain in the Swiss Pennine Alps of Valais, forming the western flank of the Simplon Pass. It lies between the upper Nanztal and the Val Divedro, 3.5 km north of the Fletschhorn, and marks a section of the Rhône–Po watershed.

The Böshorn rises to 3,268 m in the Valais Alps and forms the western flank of the Simplon Pass. It lies 3.5 km north of the Fletschhorn and marks a section of the Rhône–Po watershed, the divide between the catchments of the two rivers.

The name Böshorn is also given as Rauthorn. The peak stands on the Rhône–Po watershed, so water on its flanks drains either toward the Rhône in Valais or toward the Po in Italy. The usual ascent leaves the Simplon Pass by way of the Bistinepass, a walk of about four hours.

The climb begins from the Chusmatte parking area near Simplon Dorf, served by regular bus connections from both the Swiss and Italian sides. The route demands alpine experience and good physical fitness due to its exposure and technical sections.

The Böshorn lies on the Rhône-Po watershed, 3.5 km north of the Fletschhorn, and its summit is also called the Rauthorn. It is reached from the Simplon Pass via the Bistinepass in about four hours of demanding walking.