Confluencia Base Camp: Aconcagua's First Camp

Confluencia Base Camp sits at 3,400 meters in the Quebrada de los Horcones, the first overnight stop on Aconcagua's normal route to the 6,962-meter summit. A day hike there covers roughly 14 km round trip from the Horcones entrance, gaining about 450 meters of elevation, and most fit walkers do it in five to six hours of moving time. No climbing permit is needed — only a day-trekking ticket, booked online in advance.

What you get for the effort is a working expedition camp: dome tents, a dining tent, rangers checking permits, and climbers nursing their first altitude headaches. It is a genuinely odd and memorable place to spend an afternoon.

Getting There and Sorting Out Permits

The Drive from Mendoza

The park gate at Horcones is about 185 km from Mendoza city along Ruta Nacional 7, the road that runs toward the Chilean border. Figure three hours each way in a vehicle, or a very long 12-hour day if you join an organized tour that handles transport, guide, and permits together. Private day trips typically leave Mendoza around 7:30 am and get back after dark.

If you are self-driving, staying in Uspallata the night before is the smart move. It puts you 90 minutes from the gate and ahead of the tour vans — the trail is quiet until about 10 am. Puente del Inca, a natural rock bridge stained ochre and yellow by mineral springs, is 3 km before the entrance and worth 20 minutes of your time on the way back.

Tickets, Reservations, and Opening Hours

Entry is paid and reservation-based. Buy your ticket through the Mendoza government's Aconcagua portal before you travel; rangers at Horcones check it against your ID at check-in, and you must check out on the way down. Park hours are 8:00 to 18:00, though trekking-day arrivals are effectively cut off at 17:00. If you plan to camp at Confluencia rather than day-hike, aim to enter before 16:00.

The summer season runs November 1 to April 30. Winter (May through October) requires a written activity request approved by provincial resolution — realistic for expeditions, not for casual hikers. Rates differ by nationality and permit type and are revised each season; fees are subject to change, so confirm current prices on the official site before paying.

The Hike and What You'll See

The Route Up the Horcones Valley

The trail starts at 2,950 meters near the Horcones ranger station and climbs gently along the valley floor, crossing a swaying suspension bridge over the Horcones River early on. You pass Laguna Espejo — Mirror Lagoon — a shallow pool that reflects the surrounding ridges when it holds water and dries to a cracked white bed by late summer. Above it, the south face of Aconcagua comes into view, and it stays with you for most of the walk.

The gradient is forgiving for the altitude. Total gain is only about 450 to 480 meters over 7 km, which is why guided outfits rate it moderate rather than hard. The thin air is the real difficulty. Pace yourself so you can talk in full sentences, drink more than feels necessary, and turn around if a headache starts building.

At the Camp

Confluencia is a grassy bench where two valleys meet, sheltered enough that the wind drops once you are inside the cluster of tents. Expeditions spend one or two nights here for acclimatization before pushing to Plaza de Mulas. There is a small kiosk operation in season selling hot drinks and snacks — a detail most trail descriptions leave out, and a welcome one when the afternoon hail arrives, which it often does.

A mandatory medical check happens at Confluencia for anyone continuing higher. Day hikers skip it, but watching a doctor clear climbers for the next stage tells you more about expedition life than any viewpoint on the road. Give yourself 45 to 60 minutes at camp before heading down.

Weather and Timing

December through February is high season: longer days, more reliable conditions, and more people on the trail. November and March are quieter, colder at the camp, and still perfectly workable for a day hike. Afternoon storms are common throughout the season — thunder, hail, sudden wind — so an early start is not just about crowds. Aim to be back below the bridge before 4 pm.

Temperatures at 3,400 meters can sit near freezing at dawn even in midsummer. A shell, gloves, and a warm layer are not overpacking. Sunscreen matters as much; the ultraviolet at this elevation burns through thin cloud.

Frequently Asked Questions

Do I need a climbing permit for the Confluencia day hike?

No. A day-trekking ticket for the Horcones valley is enough, and it is cheaper than an ascent permit. Book it online before you arrive, because rangers will not sell you entry at the gate without a reservation slot.

How long does the hike to Confluencia take?

Most walkers reach camp in 3 to 4 hours and descend in 2 to 3. Plan on 5 to 6 hours of walking plus an hour at camp, and add the transport time if you are coming from Mendoza — that is what turns it into a 12-hour day.

Can I stay overnight at Confluencia without climbing Aconcagua?

Yes, overnight stays are allowed with the appropriate permit, and camping there is the standard way to acclimatize before Plaza de Mulas. Enter before 16:00 and register at the ranger station, since check-in and check-out are mandatory.

Is altitude sickness a risk at 3,400 meters?

It can be, even for fit hikers coming straight from Mendoza at 750 meters. Headache, nausea, and breathlessness on mild exertion are the usual early signs. Descend if symptoms worsen rather than waiting it out — the trail back down is short and the drop is fast.