Due to its geographic conditions, the kingdom of Chile remained isolated during the winter from the far away province of Cuyo, under its jurisdiction, and from the city of Buenos Aires, with which it began to have a great commerce, and that in addition served as an intermediary point over its relations with Europe.

After hearing the opinion of many people, President Guill y Gonzaga, looking for a remedy to that situation arranged in 1765 the construction of sentry boxes of lime and brick, that could serve for asylum to the travelers in those days of bad weather. Under the direction of the lieutenant colonel of engineers, Don Juan Garland, and of an unknown Irish official called Don Ambrosio O'Higgins, there were selected the sites for building those constructions. Ambrosio O'Higgins had to work hard to obtain a great position due to his talent and activity.

In the last months of the year 1765 and the beginning of 1766, O'Higgins, raised three sentry boxes of that class, that later were increased with other four ones. These sentry boxes served effectively to the travelers who ventured themselves to pass the mountain range in the months of winter.

Don Juan Garland who, as it seems, had a true merit as a military engineer, was one of the many Irish officials who, by those years, took service in the armies of the king of Spain.

In 1762, the governor Guill y Gonzaga sent him to Valdivia, in order to raise the plane of the seat and to study the innovations that were supposed to be settled in its forts and defenses. He came back to Santiago to make this work. After he carried out this commission in Santiago ( 1765), he returned to Valdivia to direct the new defensive installations and, as a consequence of the death of Don Felix de Verroeta, he was named to carry out the position of governor of the seat during five years, leaving there very good reminders. Having obtained permission to return to Spain, Garland passed away during the trip in 1775.

 

About Don Ambrosio O'Higgins, who began to serve under the orders of that one, we will have to speak extensively about him more ahead.

In office he directed to fray Julian de Arriaga, minister of Indians, on the 8th. March 1766, Guill y Gonzaga gives him account of the previous information he received from the engineers and practical men he could consult, but without naming no one of these,probably not to mention the nationality of Garland and O'Higgins.He explains the origin of this work:

"The remarkable damage that was originated for closing the mountain range during six months a year, lacking of warnings to H.M through the channel of Buenos Aires, and the utility of having news of some enemy attempt on time, in order to take the advisable precautions and measures, made me firmly reflect to smooth this disadvantage , with the intention to allow this channel to be passable in winter. About this matter I had several conferences with the engineers; and as one of them (this one was Don Juan Garland) practiced this way at the most rigid weather of the year on 1763, he was able to assure how reasonable was the project, with the settlement of six shelters for refuge of the travelers, at provided distances of the way.

These shelters were constructed on arcs, and in such disposition that they were not absolutely covered with snow, indicating those sites that were considered more able to load less portion of snow, or to be prevented from winds. In May (of every year) they were provided with food and firewood, and the keys of its doors were kept in this city and the one of Mendoza, to lend them for post office serving and passengers from each side of the mountain range, assuring that both were practicable."

After giving account of the information received from the experts and the commitments to carry out this work, Guill y Gonzaga finishes his office with these words: "Besides the foundations that I exposed to H.M.; and as the channel of Havana is so far away from this southern America, as so provided the one of Río de la Plata, once this disadvantage is cleared, it seemed to me very suitable for the real service to advance this subject as far as possible, in case it would be pleasant to H.M."
In effect, having established the King in 1765 that every two months there should leave from Spain a ship mail to Montevideo with the correspondence for Buenos Aires, Chile and Peru, the traffic by the mountain range received much greater importance.