The first destination will be the large town of San Isidro de el General located to the west of the peak and national park. To reach San Isidro from San Jose, take one of the hourly (seven days a week) buses to San Isidro from the bus terminal at Calle Central and Avenida 22. It's a three hour ride.
From San Isidro, you must take another bus to San Gerardo de Rivas. The bus takes two hours and leaves at 5 AM and 1 PM each day. Get off the bus at the Parue National Chirripo ranger station.
The first day is a long one. It is recommended that you arrange permits the day before in order to get an early start the next morning. At the very latest, a 6 AM (earlier is better) start is recommended. It is much better to do the first section of the trail in the cool of morning as it can be very hot later in the day. Make sure you carry enough water along for the first 7.5 kms as none is available. Most of the hostels and lodges can arrange transport early in the morning to the trailhead. It's about 2 kms from the ranger station to the trailhead.
The first day to the Base Crestones (hut) is 14.5 kms with 2200 meters elevation gain. From the ranger station, follow the signs to the trailhead. The trail immediately begins its steep climb to the "Water Ridge". You will pass some cleared land for cattle grazing before you enter the rainforest. Keep an eye out for Quetzels (birds) along the way. After 7.5 kms of steep walking, you will reach "Water Ridge" which is a picnic area and a water tap. Stock up with water here, as there is no more available until you are near the Base Crestones. Keep an eye out for both spider and white face monkeys in the area; we saw several just below the lunch area on our return trip.
After enjoying a well deserved break, continue of the steep trail. The three uphill sections have names. The first is Cuesta de Agua (Water Hill), the second Monte Sin Fe (mountain of no hope), and the third is La Cuesta de los Arrepentidos (repentance hill). The first and last hills are the longest and steepest. At the top of Monte Sin Fe, you reach the Paramo. A few kms after that you will cross a stream on a bridge. From here its one long steep section to the Base Crestones Hut.
After spending the night in the hut, follow the trail posted for Cerro Chirripo, ignoring lesser used side tracks such as the one to Cerro Ventisqueros. The trail is steep at the end and has some scrambling, but anyone whom made it this far should be able to handle it.
The views from the summit are spectacular. If the weather is exceptionally clear (rare) you can see both oceans. There are many rugged glacier-carved peaks all around. Between Cerro Ventisqueros and Cerro Chirripo are the Lagos Chirripo. The largest one is the highest lake in Central America.
There are other peaks in the area to climb as well so it is recommended that you spend another night at the Base Crestones in order to climb some of the other peaks on day two. See some of the other mountain pages for more details:
On the same hike you can also head to other seldom visited peaks such as Cerro Uran, Loma Larga, or Cerro Laguna or even hike across Cerro Uran to Rio Blanco and easily spend five days doing so.
Bring your own sleeping bag when stayin in the hut. Also, this mountain gets quite a bit of rain, so bring adequate rain gear. It's also quite cool at night and when cloudy. Water is sometimes scarce along parts of the trail, so take plenty of water in your pack.