According to the 1991 census, Caleta Olivia has 28.000 inhabitants. Its natural port was one of the points selected by the Marina Argentina to unload materials for the installation of the telegraph from Buenos Aires to Cabo Vírgenes. Ship lieutenant Exequiel Guttero, in command of the Navy steamship "Guardia Nacional" discovered on 20th November 1901 a cove appropiate for that purpose in the area where they had to perform the task, that he named Olivia.
In the report that he sent to his superiors, he described the chosen place:
"On the 22nd May, I parted from the anchorage place (Punta Borja, at present Comodoro Rivadavia), and continued towards Bahía Langara. Once in the centre of the bay, I anchored one mile from the coast in 12 braces of water on a sandy bottom, and sent a boat to find out wether the beach was able to be boarded to unload the materials for the Telegraph.
After examining all the bay in the steamboat, and given the impossibility to moor with any kind of vessel due to the stone surrounding all the beach, I decided to set out and inspect the coast towards Fondo Beach to find a pier. In this operation, the bad weather surprised me and forced me to anchor on the coast and hold up on the engine during the hard night. The next day at dawn, since I could not keep up any longer, I weighed anchor and headed back to Punta Borja, and when I arrived, I told the Inspector of the Telegraph under construction that given the impossibility to unload the supplies in Langara, I would do it in the closest part of the coast where the operation was possible."
"On 26th May, while inspecting the coast, I saw a spot protected between two shoals. It was a small cove, very deep and sheltered, that permitted in very good conditions the unloading of 800 palms and 700 wire rolls."
"On 28th May, the unloading finished, I parted to Santa Cruz..."
This enterprise was carried out fostered by General Roca, and it was constructed between 1900 and 1905.
On 16th November 1901, the Telegraphic office started operating in Caleta Olivia, 3 km. distant from the port, since there was no drinking water on the spot. Its three employees were chief Calixto A. Melzi, who had already been the first boss for a few months in Comodoro Rivadavia, Arturo B. Guerra and Manuel Espinosa, the first known inhabitants in the place.
Moreover, taking into consideration that the new office was isolated from all urban areas and many kilometres far from a resource centre to acquire the necessary elements to satisfy the needs of its personnel, they were provided with several food items, which it is interesting to point out in order to describe their gastronomic austerity:
100 kg. crackers, 70 kg. rice, 50 kg. sugar, 70 kg. noodles, 70 kg. mate, 90 kg. flour, 50 kg. cassava flour, 50 kg. dry beans, 1 kg. paprika, 15 kg. tobacco, 3000 smoking paper leaves, and 2 dozens of boxes of matches. They also received a flock of 200 ramboullet sheep with 4 rams exclusively for the consumption of the employees.
The building, constructed in sheet metal and timber in a 3.250 m2 lot, on the base of a unique model used for all the other offices of the line, the remains of which could still be seen in cape Blanco and Bahía Laura, was used both as an office to deliver the postal and telegraphic services, and as lodging place for the employees.
Since the office was distant from the coast, it was inconvenient for those who had settled on the sea shore, and aroused the consequent complaints, which were only taken into consideration in 1922, when the same building was tranferred to the village on the coast, where it remained in activity until 3rd September 1937, when it burnt to ashed, with all it contained, thus forcing the Post Office to operate in a rented building.
Only some of the bosses of the office in those first years have been recorded, but it is worth mentioning them here: from 1907 and for several years, Miguel A. Tamburini; in 1917, Ricardo Arana; and around 1925, Agustín T. Rasca.
By the end of the XIX century, there was extensive sheep breeding in this region of Patagonia, and the wool was shipped from this port after some difficult loading tasks, since the installations were extremely rudimentary. By this time, livestock raising and the estancias in general were developind, and Caleta Olivia was the centre of them.
Another activity that produced an expansion was petroleum. In 1921, the research on the Flanco Sur started and after years of failures and frustrations, in 1944, oil finally sprang in Cañadón Seco, a place near Caleta Olivia, at a depth of 1000 m.
Since November 1995, the oil-deposit 0-12 was declared Monumento Histórico Provincial.
This activity originated the construction of neighbourhoods and the growth of the labor demand. People from different provinces of the country arrived in search for working opportunities.
At the intersection of the streets Independencia, Güemes and Av. San Martín is the Monument to the Oil Worker: El Gorosito, a sculpture by Pablo Daniel Sánchez.