Latvia lies on the eastern shores of the Baltic Sea on the level northwestern part of the rising East European platform, between Estonia and Lithuania. About 98% of the country lies under 200 m (656 ft) elevation. With the exception of the coastal plains, the ice age divided Latvia into three main regions: the morainic Western and Eastern uplands and the Middle lowlands. Latvia holds over 12,000 rivers, only 17 of which are longer than 100 km (60 mi), and over 3,000 small lakes, most of which are eutrophic. The major rivers include the Daugava, the Lielupe, the Gauja, the Venta and the Salaca. Woodlands cover around 52% of the country (Pine - 34%, Spruce - 18%, Birch - 30%). Other than peat, dolomite, and limestone, natural resources are scarce. Latvia has 531 km (330 mi) of sandy coastline, and the ports of Liepāja and Ventspils provide important warm-water harbors for the Baltic coast. Latvian Railways is the main state-owned railway company in Latvia. Its daughter companies both carry out passengers services as well as carry a large quantity of freight cargo, and freight trains operate over the whole current passenger network, and a number of lines currently closed to passenger services.