By the middle of the 16th century, there was permanent housing in Uurainen. The inhabitants practised agriculture and especially fishing. Salted Baltic herring and whitefish were in high demand. During the fast, plenty of salted fish was sold especially to the Baltic Countries. At the end of the 16th century, the inhabitants of Uuras and Suonionsaari had even large vessels because they had been used for transfer of food, men, and even detachments in the Gulf of Finland. Some freight sailors even practised export past Vyborg. After the peace of Stolbova from the 1650s freight sailing formed the most considerable part of peasant sailors’ livelihood. The tax revenues of Inkerinmaa, grain, hemp, and leathers had to be transported to Stockholm and raw materials for Finnish ironworks had to be imported from Sweden. Firewood transportation also had an important role in freight sailing. People in Ravansaari and Uuras were skilful pilots who were needed in the archipelago and especially sails to Vyborg harbour demanded professionals. Pilots became a valued profession. Warehouses were built for timber and tar on the shores of Uuras and Ravansaari at the end of the 17th century. Goods were transported to the warehouses with small vessels as later in the 20th century.
The strong increase in sawmill industry after the 1750s also changed the economic structure of Uuras archipelago. A lot of timber was sawed and export increased rapidly. The cramped Vyborg harbour could not store all the timber and thus Ravansaari and Uuras became natural storage and harbour areas. Diverse timber companies built their own warehouses on the shore areas and a new pier was built in the course of years.
After the Great Northern War, the meaning of Uuras archipelago increased from the viewpoint of defence. Small fortresses were built at the tips of Röyväli and Kirkkoniemi in the 1790s. They had to face the Swedish navy in 1790 in front of Uuras. The attempt to sail to Vyborg rebounded before the narrows of Uuras archipelago and Swedes managed to escape to the Gulf of Finland only with difficulty. A fortress was built to the northern tip of Suonionsaari in 1809 and a large fortress in Ravansaari in 1855-1860, and an equivalent fortress to the northern tip of Uuras in 1860-1870.
Saimaa Canal opened in 1856 induced a strong growth in the harbour when the timber from Vuoksi area came to Vyborg and Uurainen for further loading. More pier places were built around the narrows of Uuras and Ravansaari and almost the whole shore area was rented or sold to diverse sawmills. In the 1920s there were 4300 metres of piers and 38 hectares of timber warehouses in Uuras and Ravansaari.
Building of the large Uuras harbour did not start until 1926 after the harbour railway was finished. A plan for development of the harbour and especially promotion of timber export was made at the same time. It was based on ship loading still taking place in the dock by means of lighters, which was fastest and most economical. The number of piers was increased in Uuraansaari by building two 150-metre loading piers with rails. A one-kilometre rail was made to the south with the rail depth of 3.5 metres. Behind the piers, 27.5 hectares were reserved to be rented for timber companies. Piers and warehouse areas were also built in Röyväli and Kirkkoniemi.
Uuras was mainly an exportation port. About 5500 vessels visited both the harbours in 1937, which was a lot considering that the harbours were closed for four months in the winter due to obstruction by ice. There was a ship connection from Uuras to Vyborg during the time of open water. The twelve-kilometre journey took about half an hour. All inland water ships coming from Saimaa or the Gulf of Finland stopped in Uuras.
Town plans were made for Uuras and Ravansaari especially for housing purposes. The Finnish Government confirmed them in 1933. There were also plans for building of a road connection to the mainland but it was not realised because of the war. Cars could be seen in Uuras only during the winter when an ice road enabled connections between the island and mainland.
Uuras, Ravansaari, Esisaari, and Suonionsaari were incorporated into Vyborg in 1932. About 8500-9000 inhabitants lived in Uuras archipelago at the end of the 1930s and plenty of new houses were built in Uuras in the 1930s. For example, a coeducational school started operation in 1923. There was a fortress in Ravansaari and Uuras as well.
There were plenty of companies in Uuras and Ravansaari. They were mostly specialised in forwarding and shipping. For example, Hagman Seur. huolinta ja laivanselvitys, shipping office of Oy Huolintakeskus Ab, loading office of Oy Kaukas Fabrik, forwarding and clearance of K. Lundberg & Co Ab, shipping office of Oy Läskelä Ab, stevedoring of W. A. Mäkelä Stevedore Oy, clearance of John Nurminen Oy, Moottoriyhtymä Salmi, shipping office of Ab T. & J. Salvesen, Oy Ernst Sohn Ltd, stevedoring of Aktiebolaget Trågsunds Stevedoring Co, Uuraan Laivaus Osakeyhtiö, Uuraan Moottoritelakka, Uuraan Puunvienti Oy, shipping office of Veitsiluoto Oy, shipping office of Wiborg Timber Co Ab, A. Wirolainen laivatelakka ja konepaja, timber yard of A. Ahlström Oy, office of Ahtaja Oy Ltd, office of Hackman & Co, and shipping office of Tornator Oy were located there.