The large mountain area between Modalen, the Voss communities and Sogn is one of the finest mountain pasture areas in West Norway. In older times this area was called Steinslandsheimen, in our times it has acquired the name Stølsheimen. Power development and protection interests have been opposed here. The core area of Stølsheimen has now been protected as a landscape protection area, while some of the oldest mountain farms have been flooded. A register in the 1970s comprised almost 40 mountain farm settlements in the central area of Stølsheimen, belonging to Modalen, Høyanger and Vik municipalities.
In 1923 Bergenshalvøens Kommunale Kraftselskap (BKK) expropriated large areas for power plants and development of hydropower started soon afterwards. Dale power station with the two first aggregates, each of 14 MW was put into operation on 17 November 1927. In the supply reservoir in Storefossen 5152 cubic metres of concrete were cast, and a modern and well-equipped power station was built.
Water discharge at the outlet of the Ekso into Eidsfjord was halved after the big hydropower development in the mountainous area between Modalen and Eksingedalen and further southward toward Evanger in the 1960s, 70s and 80s. In an attempt to amend the changed environmental conditions in the waterway the developer built 35 small dams in the river.