The narrow, wooded Mortirolo road climbing above the Valtellina.

EXTREMEIT · Lombardia · SS42 dir/A

Passo del Mortirolo

Eleven kilometres of the hardest climb in Italian cycling, called corner by corner.

Mazzo di Valtellina to the Passo del Mortirolo, the hard side.

Corners coloured by severity · tightest in red

11.3km
LENGTH: 117
CORNERS CALLED: 9
HAIRPINS: 10.3
CORNERS / KM: +1284m
CLIMB: 1845m
HIGH POINT: 11.3%
AVERAGE GRADIENT

The Mortirolo is short and it is savage. From Mazzo di Valtellina the road climbs to 1,852 metres in a little over eleven kilometres, averaging more than eleven per cent the whole way. That is why it became the mountain the Giro d’Italia uses to break a race, and the climb Marco Pantani made his own in 1994.

It does not look like a famous road. Most of it is tagged as an unclassified road in OpenStreetMap: single track, no lane markings, no lighting, walled in by trees. Every corner below is generated from that road’s real geometry, and the app speaks them in the same notation.

Only nine of the 117 calls are hairpins, which is what makes the Mortirolo unlike the passes it is usually listed beside. This is not a switchback staircase. It is a narrow road that simply never straightens, at over ten calls per kilometre.

The grade histogram tells the same story from the other side: this is a road of 3s and 4s arriving continuously, with almost no open running in between. On a climb this steep and this blind, knowing what the next corner does matters more than on a road twice its length.

THE STAGE MAP

Every corner, where it actually is.

startH · hairpinSQ · square123456

THE CLIMB

Elevation profile.

557 m → 1845 m over 11.3 kmvertical scale ×2.1elevation from a terrain model, not a survey

CORNER MIX

What the road is actually made of.

9hairpin
2square
301
82
173
284
205
36

THE PACENOTES

All 117 calls, in order.

Every call Tornante makes on Passo del Mortirolo, in order. Distances are from the stage start to the corner’s turn-in.
At	Call	Notes	Altitude
0000m	R1	long	557 m
0175m	L2		561 m
0270m	L4		565 m
0304m	R square		567 m
0381m	L1		573 m
0434m	R1		579 m
0463m	L1		581 m
0521m	L3+		588 m
0583m	R1	long	596 m
0653m	L3		609 m
0705m	R3		616 m
0754m	L1	long	623 m
0838m	R4		632 m
0902m	R4		643 m
0964m	L3		652 m
1030m	R4		658 m
1099m	R4		665 m
1271m	R4		699 m
1337m	L4		712 m
1407m	R2	long	727 m
1639m	L hairpin		781 m
1850m	R hairpin		793 m
2091m	L2		812 m
2173m	R3-		819 m
2252m	L1		828 m
2311m	L1	long	835 m
2408m	L5-		842 m
2466m	R4		847 m
2667m	R5		867 m
2727m	L4		875 m
2832m	R3		887 m
2901m	L3		893 m
2950m	R square		898 m
3006m	R1		908 m
3057m	L4+		919 m
3192m	L5		939 m
3312m	R4		953 m
3363m	L4		960 m
3452m	R5-		979 m
3560m	L hairpin		1000 m
3651m	R5		1016 m
3762m	R1	long	1026 m
3926m	L hairpin		1058 m
4036m	R5		1079 m
4148m	R5		1085 m
4214m	L3		1090 m
4256m	R4-		1094 m
4356m	L5-		1110 m
4446m	R1	long	1123 m
4532m	R3-		1136 m
4574m	L1+		1140 m
4618m	L1		1145 m
4680m	R4		1153 m
4803m	L1	long	1175 m
4896m	R1	long	1189 m
5037m	R5		1206 m
5138m	R5		1214 m
5253m	R3		1220 m
5305m	L3-		1224 m
5348m	L1	long	1228 m
5420m	R1	long	1236 m
5485m	L5+		1242 m
5539m	L1	long	1249 m
5637m	R5		1265 m
5714m	L5		1274 m
5770m	R1	long	1278 m
5996m	R5		1317 m
6145m	L hairpin		1329 m
6236m	R3		1343 m
6366m	L5		1364 m
6587m	R6		1388 m
6716m	R5		1398 m
6814m	R1	long	1408 m
6891m	L1		1422 m
6954m	R2		1431 m
7033m	L1	long	1440 m
7092m	R1	long	1443 m
7140m	L hairpin		1447 m
7225m	L4		1459 m
7310m	R6		1470 m
7619m	R1	long	1503 m
7686m	L3		1509 m
7733m	R4		1517 m
7843m	R4		1530 m
7893m	L hairpin		1537 m
8053m	L4-		1552 m
8168m	R1	long	1564 m
8295m	R4		1577 m
8351m	L3		1579 m
8405m	R4		1580 m
8641m	L5		1600 m
8762m	L4		1612 m
8800m	R2		1616 m
8866m	L4		1622 m
8947m	L3		1630 m
9021m	R2		1641 m
9120m	L3		1655 m
9189m	R5-		1661 m
9313m	L5		1674 m
9524m	R4		1690 m
9675m	L2		1704 m
9740m	R3		1711 m
9816m	L hairpin		1719 m
9984m	R1	long	1738 m
10086m	L1	long	1753 m
10190m	R5		1764 m
10277m	R2+		1770 m
10360m	L4		1773 m
10453m	L4		1779 m
10554m	R1	long	1785 m
10618m	L1	long	1790 m
10711m	R hairpin		1799 m
10873m	L4-		1808 m
10946m	L1	long	1812 m
11032m	R4		1824 m
11165m	L4		1837 m
11239m	R6		1843 m

How to read these notes

A call is a direction and a grade: L or R, then 1 (tightest) to 6 (barely a bend). A + or − means the corner sits near the edge of its band. Corners too tight for the ladder are named instead: hairpin, open hairpin, square.

The Notes column carries what gets added to the grade, such as long for a corner that holds its angle well past the usual, and Altitudeis the height at the corner’s turn-in.

The full call reference explains every call, the geometry that earns it, and how each one sounds in English and Italian.

HOW IT SOUNDS

The opening of the stage, as spoken.

0m“20, right 1 long”
175m“60, left 2 and left 4”
304m“20, square right and left 1”
434m“20, right 1 and left 1”
521m“20, left 3 into right 1 long”
653m“20, left 3 and right 3”

QUESTIONS

Passo del Mortirolo, in brief.

How steep is the Mortirolo?

This stage gains about 1,285 m over 11.3 km, an average of roughly 11%, which is exceptional for a climb of that length. We do not publish a maximum-gradient figure, because the open terrain model available for this road cannot resolve individual ramps well enough for that number to be meaningful.

Which side of the Mortirolo is the hard one?

The Mazzo di Valtellina side, which is the one on this page. The approaches from Monno and Grosio are both longer and gentler.

Is the Mortirolo open in winter?

No. OpenStreetMap records the pass road as closed from November to April. Check locally before you go, because these dates move with the snow.

WHERE THIS COMES FROM

Measured, not written.

Every corner on this page was generated by the same engine that runs in the app, from the road’s own geometry: Strada del Mortirolo (SS42 dir/A), mapped by OpenStreetMap contributors and tagged unclassified, asphalt. The engine is deterministic: the same road always produces the same notes, so this table is exactly what the app will say to you.

Elevation comes from an open terrain model rather than a survey, so altitudes are close but not exact. Corner grades are computed estimates, not measurements of how the road should be driven.

Drive it with the calls.

Passo del Mortirolo ships with the app. Start the stage and Tornante speaks each of these calls as you reach it, timed to your GPS, so your eyes stay on the road rather than on a screen.

Download on the App Store

NEXT ROAD

Other called stages.

Corner density on this stage: 10.3 calls per kilometre.