As Ryan Wilson makes his way from Colombia to Santiago de Chile by bike, he tackles one of the longest climbs in the world, on a road that straddles the Chile and Argentina border.  Follow along as he explores the stunning desert landscapes and night skies of the region while crossing Paso Agua Negra.

When I rode through the Andes back in 2018/2019, I ended up crisscrossing back and forth between Chile and Argentina no less than 14 times.  With the way the border between the two countries cuts straight along the divide of the Andes, this tends to be where all of the best riding in this region exists.  Still, 14 is only the tip of the iceberg along the 5,308km (3,298 mile) border and there were many left to see.

One that I didn’t get a chance to summit on my first trip through was Argentina and Chile’s highest altitude frontera known as Paso Agua Negra.

It’s tucked into the arid central Andes, which are famous for their night skies.  Low light pollution and clear skies for most of the year bring people here from all over the world, and it’s why you’re bound to spot a handful of observatories when you look around from any given peak in this region.

Ruta Antakari

To avoid some of the busier sections on the lower slopes of the road that leads up from sea level to Paso Agua Negra at 4753m (15,593ft) a whopping 220km (137 miles) later, I opted to take the scenic route toward a quieter nearby valley instead, weaving in dirt roads wherever I could find them.

This had me zig-zagging between Valle del Elqui and the Río Hurtado valley along routes forged by indigenous communities in the region since the 1400s.  The landscape here is dusty the flora is spiky.   When you get away from the coastal breeze and marine layer, the weather is scorchingly hot under the midday sun and the roads are predictably steep — it is Chile after all.

A long climb out from La Serena led me up toward a ridge line that gave me my first views of some of the famous Chilean observatories in the distance.  After feeling totally sapped of energy for much of the day, the relief that came from the sun disappearing behind the mountains gave me an extra burst, which allowed me to finish the rest of the climb after dusk. Usually, I try not to ride too late when I have to find a wild campsite, but I couldn’t help but take advantage of the cool nights and the bright moon.

Eventually, I found a spot to camp in the dark and woke up to coastal fog enveloping my tent in the morning, before rapidly burning off as the day started heating up.

Río Hurtado

I made my way through desolate cacti-lined valleys on a nice dirt road and cruised down a long descent to the Hurtado Valley.  The temperatures were soaring, but at least there was some shade in this valley with the help of the trees that linethe river.  Here, I saved myself from the hottest hours of the day by spending a couple of them in the shade of a small roadside tienda (shop).

Further up in the craggy valley, the pavement ends, and a dirt road that is often traveled by local cyclists on the weekends snakes its way up more rapidly.   The views started to open up near the pass and I found a little spot to wild camp along a small road-turned-goat trail where I got another glimpse of the Chilean night sky on a moonlit night.

It’s no coincidence they call this the Route of the Stars (Ruta de la Estrellas).

The Long Climb from Vicuña

Descending into Valle del Elqui in the morning, I found myself in the small town of Vicuña, which turned out to be one of my favorite Chilean towns that I’ve visited.  Not too big to be hectic, but enough activity around to be interesting, and set in amongst these amazing desert hills.  If I had to make a list of places I could live one day, I’d say Vicuña definitely makes the cut.  It was a perfect place for a couple of days’ rest and to catch up on work.

A short time in the city combined with the hint of mountains that I could see in the distance had me itching to hit the long road to the pass, so I loaded up on a handful of days worth of supplies and jumped onto some dirt tracks that parallel the main road, in hopes to avoid the last bit of traffic before it mostly dies down.

No more than 10 minutes after I got out of the town, I got waved down by a local farmer who was off the side of the road.  He told me to wait a second before disappearing, and he reappeared moments later with a paper bag filled with locally grown figs, one of the staple crops of the Elqui Valley along with grapes, papaya, and avocados.

Seeing that fresh figs don’t travel particularly well when stuffed into panniers on a bumpy dirt road, I had no choice but to eat as many as I could manage on the spot.

Third Wheeling

Shortly up the road, I stopped at a shop, one of the last on the route, to sort through my supplies and make sure I was stocked up on beans and queso.  That’s when I ran into Paul and Hera from the Netherlands, who are in the midst of their own trip across the Andes, heading north.  Hera has been traveling by bike for many years now and Paul recently left his long-time job as a designer at Santos Bikes (he helped design the bikes they were riding!) to hit the road long-term.

While we were heading in different directions overall, we each had another 300+ kilometers of riding east before splitting north and south, so we’d still be able to share a handful of days of riding and camping together on our way over the pass.

No Man’s Land

From the immigration post in Chile where you collect your passport exit stamp to Argentina’s immigration post is about 167 kilometers, which means most touring cyclists will spend 2-3 days “between” countries.  Save for a couple of seasonal shepherds tending to their goats in these remote mountains, there’s nothing up here.

The colorful, mineral-rich mountains and the sparse vegetation give it the feel of the northern parts of Chile and Argentina’s Puna de Atacama, but this road has a river running down the whole valley, which makes it a little bit easier in terms of planning than most of the Puna roads I’ve done in the past.   On many, it’s not abnormal to have to haul 10-15L’s of water at a time to last you 2-3 days, and that extra 10 kilos makes all the difference.  It’s amazing how much one little strand of water makes life so much easier.  Here, it’s just a matter of carrying enough food to get you to the other side.

The Last Push to the Top

The western slopes of Paso Agua Negra offer some of the best views that I’ve come across on tour.  From the layered, colorful mountains to the glacier-capped peaks.  Doing a climb that ascends from the sea to these heights comes with challenges in terms of altitude, but with that comes an impressive diversity of landscapes.

Having spent a couple of weeks down at sea level since my last jaunt through the higher zones of the Andes, I wondered how I would do with a straight ascent up and over 4,753m.  It’s always hard to know how fast you’ll lose that acclimatization.  Thankfully, the very gradual nature of the first couple of days of this climb helps ease you into it.

However, the “easing” stops in classic Chilean fashion, a little before the very top of the pass, when the air is at its thinnest, and you’re already feeling the effects.  That’s when the road suddenly cranks up to 10%+ for the final push over the summit.

I took turns pushing a bit and riding a bit, turning the pedals as slowly as I could to preserve the tiny amount of energy I had left.  I looked at my phone to check the map in one moment, and then what felt like a half hour later I stopped again and had another peek, hoping to see that I’ve cleared a big chunk of the remaining ascent… yet it’s like I barely moved.

What goes up…

Little by little, I finally got there and was rewarded with some amazing views down the Argentina side.  It would start with a series of sweeping switchbacks, twisting and turning their way down into the valley.   It was the beginning of a nearly 90km (56 mile) descent, from the foot of a glacier to the lower slopes of the eastern Andes.

A headwind on the descent couldn’t break our spirits as we pace-lined toward civilization.  It had been about 2.5 days out in “no man’s land”, and the immigration officers were expecting us as you have to give an estimate on the number of days it will take you to cross between the two border posts.  We arrived a little ahead of schedule and pushed on toward our first stop in Argentina, in the quiet town of Rodeo.

In classic Argentine fashion, none of the ATMs worked and there were no official currency exchanges, so I was left to beg anyone I could find to swap my few remaining emergency supply dollars for pesos.  It was just barely enough to get a spot in a campground for a much-needed rest, an even more needed shower, and a meal for the night.

Minor headaches in dealing with Argentina’s quirks aside, it was great to finally be back on this side of the Andes.  There’s an immediate change of pace that is noticeable as everything slows down in Argentina.  From the long midday siesta when 95% of the shops close and the streets clear for hours at a time, to the more laid-back approach to just about everything.  I was looking forward to spending my last few weeks in South America with some tranquilo time riding between Argentina’s idyllic towns.

Stay tuned here for more stories from the road as I make my way to Santiago de Chile, and big thanks to Tumbleweed Bikes for sponsoring my reportage!

See the Prospector frame he’s touring on and more at Tumbleweed Bikes.