El Centro had also become the principal wholesale center of the area and the location of the Imperial Irrigation District (IID) administrative offices. Because of its strategic location near rail lines and Highway 80 and 99, El Centro in the 1940s was also becoming the shipping center for vegetables in the south end of the Valley. The principal industries of El Centro in the forties revolved around agriculture––fruit and vegetable packing and shipping, ice plants, a flax fiber plant, box factories, and concrete pipe and brick yards. By the 1970s agriculture was still an important part of the City's economic life. Imperial County has become one of the most agriculturally productive areas in the country and more than 35 growers and shippers still operate in El Centro.