Alto de Letras is 49.6 miles (79.9 km) of climbing from Mariquita (Tolima), at about 1,600 ft (490 m), to the Letras páramo at 12,064 ft (3,677 m) in the Central Cordillera. It adds up to 11,729 ft (3,575 m) of total climbing at an average of 4.5%. There is nothing like it in Europe: it is one of the longest paved climbs on the planet, and in a single day you go from the heat of the Magdalena valley to the cold of the páramo.
What the climb is like
The average is misleading, because Letras is not one continuous ramp but a string of climbs with descents in between (which is why total climbing is about 1,300 ft / 400 m more than the net elevation difference).
- Mariquita to Fresno. It starts with two hairpins and 10% ramps, followed by about 3.1 miles (5 km) at 7%. Then come false flats, kickers up to 8% and the odd descent. This is the hottest part.
- Fresno to Padua (km 40). Long straights and irregular kickers. Near Padua is the hardest pitch of the climb: about 300 m (1,000 ft) at 10-11%. Wikipedia gives a maximum of 11%; Climbfinder, which averages every 100 m, stops at 8.6%.
- Padua to km 60. About 3.7 miles (6 km) at 6%, then mixed terrain, mostly above 6%. Around km 60 there is a 0.9-mile (1.5 km) descent and roadside restaurants where you can eat.
- Last 12.4 miles (20 km). Almost 6.8 miles (11 km) at 7% through shady valleys, a short descent, another 1.5 miles (2.4 km) at 7.6% and a final stretch of about 2.5 miles (4 km) near 6% to the plateau at the top.
The figures vary by source: Climbfinder gives 49.6 miles (79.9 km) and 11,729 ft (3,575 m); Wikipedia 50.1 miles (80.7 km) at 3.9% on average (calculated from the net elevation difference, not total climbing); PJAMM about 50 miles (80 km). We use Climbfinder’s because it measures total climbing, which is what your legs feel.
Its history
Letras has been part of Colombian cycling history since the first Vuelta a Colombia in 1951, when Efraín Forero crossed it first on the way to Manizales. It has been climbed many times in the Vuelta a Colombia and the Clásico RCN. It has been used as a stage finish only once: in the 2017 Vuelta a Colombia, on a stage from La Dorada won by Miguel Ángel Reyes.
When to go, weather, water and traffic
You can ride it all year, but the rainy seasons (April-May and October-November) bring more fog and a higher risk of landslides. Start early: the humid heat bites at the bottom, and the afternoon usually clouds over at the top. At the summit, 12,064 ft (3,677 m), the air holds a third less oxygen than at sea level, and it is cold even if you were roasting below; bring a jacket, gloves and leg warmers for the descent toward Manizales.
There is water and food in Mariquita, Fresno, Padua and at the roadside restaurants around km 60; above that, not much. It is the road between Mariquita and Manizales, with buses and trucks: use a rear light and check road conditions, as landslides close it at times. On the other side is the Manizales side: 19.6 miles (31.6 km) at 5.7%.
What gearing to use
The grade rarely goes past 8-10%, so a 34x28 is enough at 3 W/kg (watts per kilogram of body weight); a 34x30 or 34x32 will feel easier in the final hours, when the altitude takes watts away. Check your combinations in the gear calculator.
Treat it like a five-hour stage: eat every 30-40 minutes from the start and ride the lower part slower than you think you should, because the heat makes you pay later.
Frequently asked questions
How long does it take to climb Alto de Letras?
A 159 lb (72 kg) rider on a 21 lb (9.5 kg) bike takes about 4 hr 37 min at 3 W/kg (216 W), 5 hr 24 min at 2.5 W/kg and 3 hr 40 min at 4 W/kg, not counting stops. Work out your own time with your weight and power in the calculator on this page.
How long is the Alto de Letras climb?
From Mariquita, between 49.6 miles (79.9 km, Climbfinder) and 50.1 miles (80.7 km, Wikipedia), depending on where you start. Total climbing is around 11,730 ft (3,575 m) because there are several descents along the way; the net elevation difference is about 10,470 ft (3,190 m).
What is the weather like on Alto de Letras?
You start in humid heat that can approach 104 °F (40 °C) in the shade in the Magdalena valley, and finish on a páramo at 12,064 ft (3,677 m) where fog, wind and cold are common. Bring warm layers for the summit and the descent.
What gearing do you need for Alto de Letras?
The grade rarely goes past 8-10%, so a 34x28 or 34x30 is enough. What wears you down is the length: more than four hours of climbing, ending above 9,800 ft (3,000 m).