River in Lombardy, Italy
Oglio Course of the river Oglio
Native name Òi / Ùi (Lombard ) country Italy region Lombardy provinces Brescia , Bergamo , Cremona , Mantua Source Valle delle Messi , as Frigidolfo branch • location near Punta Valmalza , Sobretta-Gavia Group , Ortler Alps , Lombardy • coordinates 46°20′31.5″N 10°27′03.5″E / 46.342083°N 10.450972°E / 46.342083; 10.450972 • elevation 3,035 m (9,957 ft)
2nd source Lake Ercavallo , Valle di Viso , as Arcanello branch • location at the slopes of Cima di Caione , Ortler Alps , Lombardy • coordinates 46°20′21.1″N 10°31′35.5″E / 46.339194°N 10.526528°E / 46.339194; 10.526528 • elevation 2,621 m (8,599 ft)
3rd source Lake Pisgana , as Narcanello branch • location Narcanello Valley , near Vedretta di Pisgana , Presena glacier , Adamello-Presanella Alps , Lombardy • coordinates 46°12′22″N 10°31′49″E / 46.20611°N 10.53028°E / 46.20611; 10.53028 • elevation 2,500 m (8,200 ft)
4th source Ogliolo branch • location Corteno Valley , on the provincial border between Corteno Golgi , province of Brescia and Aprica , province of Sondrio , Lombardy , near Zappello dell'Asino • coordinates 46°08′52″N 10°09′54.2″E / 46.14778°N 10.165056°E / 46.14778; 10.165056 • elevation 1,172 m (3,845 ft)
Source confluence confluence of Frigidolfo and Narcanello branches • location Ponte di Legno , province of Brescia , Lombardy • coordinates 46°15′32.7″N 10°30′28.7″E / 46.259083°N 10.507972°E / 46.259083; 10.507972 • elevation 1,253 m (4,111 ft)
Mouth Po • location
at the municipal border between Marcaria and Viadana , province of Mantua , Lombardy • coordinates
45°02′40″N 10°39′37″E / 45.04444°N 10.66028°E / 45.04444; 10.66028 Length 280 km (170 mi) Basin size 6,649 km2 (2,567 sq mi) Discharge • average 137 m3 /s (4,800 cu ft/s)
Progression Po → Adriatic Sea
View of the confluence of the Frigidolfo branch (left) and the Narcanello branch (right), Ponte di Legno River Oglio at Berzo Demo , Val Camonica
The Oglio (Italian: [ˈɔʎʎo] ; Latin : Ollius or Olius ; Lombard : Òi , Cremonese : Ùi ) is a left-side tributary of the river Po in Lombardy , Italy . It is 280 kilometres (170 mi) long.
In the hierarchy of the Po's tributaries, with its 280 kilometres (170 mi) of length, it occupies the 2nd place per length (after the river Adda ), while it is the 4th per basin surface (after Tanaro , Adda and Ticino ), and the 3rd per average discharge at the mouth (after Ticino and Adda).