At Calendario Mancilla, there is a Carabineros border control outpost. They asked that we fill out an expedition hiking form since the GPT follows a little used route. After discussing the route, the Carabineros informed us that entering Argentina at Lago Diablo, which is the current GPS route, is illegal. There is an alternate route, as described below, which remains in Chile that we decided to take instead.
From the Chilean border control, follow the gravel road for a short distance and turn onto a trail marked by white sign with green lettering that says “Rio Obsticulos” as shown by the current GPS track (hikers may want to consider following the alternate listed at the end of this section description to and from Glacier O’Higgins because that trail is of much higher quality, more scenic, and more pleasant than the one that follows the bank of Lago O’Higgins/San Martin).
After crossing the wooden bridge, hike along an ill-defined track that winds up and down the shoreline of Lago O’Higgins/San Martin to the land bridge north of Lago Chico. There is one residence as well as the occasional small camp spot along this route.
There is another residence located on the east side of the land bridge, and hikers may pass through a wire gate on north side of the corral. A faint trail heads west and terminates at the bank of the narrow channel that connects Lago O’Higgins/San Martin and Lago Chico. A packraft is required to cross this channel.
There is another residence on the west side of the channel. When the large ferry out of Villa O’Higgins is functional, it drops people off near this residence so they may hike the Sendero a Candelario Mancilla which is marked with orange and white blazes. This trail is well-formed and climbs the hill south of the residence. After exiting the treeline, be aware that there is limited camping for many kilometers. From this point, the route is very exposed and there is no cover until the route re-crosses Lago Chico.
Glacier O’Higgins is beautiful; it is composed of glistening blue ice that terminates into the lake. Sadly, as the University of Valdevía has documented, the glacier is receding at an alarming rate and is in danger. As you enjoy the views, the trail continues to wind up and down above the lake but eventually disappears. Navigation is easy due to a lack of vegetation, but camping is poor due to exposure and the steep terrain.
An orange refugio is located 2 km from Lago Chico on the glacial moraine. It is equipped with solar panels and is a good place to ride out a storm. The route continues down rocks and sand to the lake edge. The lake paddle is very pleasant, and depending on the season, it may involve weaving through icebergs to get to open water. Be careful not to get too close to the icebergs! Many of them are unstable and falling ice is common.
The GPS route indicates a northbound float on Lago Chico for approximately 4 km until take-out, but high winds forced us off of the lake early. We exited at the southern end of Lago Chico and from there faced a very difficult, brushy, and steep climb up to a trail at about elevation 750 m. Weather permitting, it may be easier to packraft all the way back to the land bridge between Lago Chico and Lago O’Higgins/San Martin. The trail on east side of the lake is well-formed, however, and there is one established campsite near a run down shack at the Lago Diablo turn off.
In order to avoid the illegal Lago Diablo crossing into Argentina, just after passing a large wooden sign that says “Sendero de Chile,” turn off to the east on a well-formed track and climb up through the forest. The track is well-formed, easy to follow, and passes by several good places to camp. There are some orange and white blazes which are hard to spot because they mark the track in the opposite direction. There is a brief cross-country section over the pass through open tundra, but the trail reappears as the route renters the trees. There are a couple river crossing, and the trail ends at the gravel road. Follow the road north back to the Carabineros outpost to inform them you made it back safely and to obtain an exit stamp.