Up the Cauca steamboats run 170 miles to Caceres; also on one of its branches, the Nechi. Through most of its length the Cauca is nearly parallel to the Magdalena, but confined in a narrow valley its course is far less smooth. Above Valdivia navigation is prevented by a stretch of 250 miles of narrow cañon and rapids; in the upper valley is another navigable section of 200 miles, from Cali to a little below Cartago. Being disconnected from the Caribbean this section must seek an outlet on the Pacific.
The San Jorge River, nearly parallel with the lower Cauca and entering the Magdalena a little farther down, is navigable for 112 miles.
At Banco, a town of 7700 on the Magdalena, a smaller boat may be taken up the Cesar River coming from the northeast; at Bodega Central, population 4000, one up the Lebrija towards Bucaramanga, to which there is another route by way of Puerto Wilches beyond. From the latter a railway, long ago planned and in operation for 12 miles, is now in construction, imperatively necessary for the development of this part of the country. The distance is 90 miles. From La Ceiba, 70 miles up the Lebrija, a mule trail leads to Ocaña, population 20,000, as well as one to Bucaramanga, which is also reached by a shorter route from a point 22 miles up the shallower Sogamoso when that is practicable.
The first railway above Calamar, found at Puerto Berrío, population 1000, nearly 500 miles south of Barranquilla, leads to the important city of Medellín. This, the oldest road in Colombia, has a break where a 15 mile ride is necessary across the mountains. When the tunnel contracted for is completed the entire length of the road will be 120 miles. Its prospects are excellent. A second railroad has Medellín, the Amagá, running 23 miles south towards the rich Cauca valley, which it will soon reach. These two roads are said to carry more freight than any others in the country.
From Mariquita, population 6000, on the Dorada Railway, an aerial Ropeway Line goes up to Manizales, in Caldas, an excellent service for freight. From Manizales a railway is building towards the Cauca River; 15 miles open, 1921.
From the Magdalena River opposite Girardot, where a bridge is being constructed, the Tolima Railway extends a distance of 99 miles to Ibagué.
Above Girardot the steamers in high water run up to Neiva, at times a little beyond. Here and higher, small boats and rafts are in general use.
Cartagena, in addition to its connection with the Magdalena River, has commercial relations with the surrounding districts, including the Chocó region, which might be served directly by ocean steamers were it not for the fact that the Atrato River is barred to them by sand at its mouth, though navigable within, 280 miles to Quibdó. As only boats of three or four feet draft can pass, and as there is no good port on the Gulf of Urabá, commerce is carried on through Cartagena by transshipment, as to cities on the Sinú River also.
From Buenaventura, the chief Pacific port, a railway leads over the West Cordillera, 100 miles, to the important city of Cali. From here the road branches south 21 miles towards Popayán, and east 16 miles to Palmira, population 27,000, then north towards Buga, population 13,555, and Cartago, population 21,500. From Buenaventura, steamboats run up the San Juan River 140 miles, which with its tributaries has 300 miles of navigable channels, for boats of 7 or 8 foot draft only, on account of sandbars at its delta.
From Tumaco several steamers ply on the Patía and other rivers to Barbacoas and other towns for many miles.