ApproachThe climb begins at the camping area of Selva de Oza, on the upper valley of the Aragón Subordán. To get there, start from Huesca or Pamplona, in northern Spain. From any one of both towns, follow road N-240 towards the other one. At Puente la Reina (88 km away from Pamplona, or 72 km away from Huesca) you will have to turn north by road A176. This is the road running alongside the river Aragón Subordán, entering the Valley of Hecho. Follow the A176 up to the village of Hecho. After crossing Hecho the road becomes sensibly worst, but goes on to the Boca del Infierno (that's a narrow pass) and Selva de Oza (see approach for Castillo de Acher). Do not leave your car at the camping area. Follow the road ahead (north ) instead, to reach in about 2 km the plain of La Mina (also known in some maps as Guarrinza). This is the spot to leave the car.
The idea is to start walking from La Mina and climb the slopes to your west. A multicoloured metal stick (pluviometer) marks the first reference for the hike. Get to it and afterwards keep following the red-and-white paint marks of the GR-11 path. They shall take you westwards and up to the Collado de Petraficha, placed north of Chipeta Alto and separating it from Petraficha. After crossing this Col turn south (left) to enter the final and wide slope of Chipeta Alto, reaching easily the summit.