Working at the breathtaking altitude of 13,000 feet (3,960 m), the missionaries climbed the hills of Potosí and placed much literature with the friendly folk. Response was excellent, and in just five years a congregation of 40 publishers was reporting.

In 1956, Richard Holman, one of the missionaries, began a study with the Ibieta family. Among those attending was eight-year-old Marco. The family made good progress for a time and became active as publishers. But in 1959 they left the congregation for unstated reasons. However, young Marco never forgot the zeal of Brother Holman, who had always come on time for the study, even on cold and rainy nights.

Meanwhile the missionaries were busy making calls from house to house.

In 1957, missionaries were assigned to the two principal cities in the area, Trinidad and Riberalta. They found that in most cases it was difficult to convince people that the Bible was not simply a man-made book with a moral code impossible to keep. But Felicia Chinchilla embraced the truth, and even when the missionaries were reassigned, she continued to serve faithfully.