The shaft ended at level 17 and is now extended to level 19. See this quote from the website below for more information.

Access to the Santa Juana Mine is via a 1,400 m crosscut from the Terneras portal to the deck of the Santa Juana winze (a vertical opening driven downward connecting two levels in a mine). This access is located on the 6th level of the Terneras Mine, which corresponds to the 12th level of the Santa Juana mine. The winze allows access from the 12th level to the 17th level. A ramp has been driven from the 15.5 level (which corresponds with the 1,600 m elevation above sea level (ASL), 400 m below surface) to the 18th level and extensive development has been completed on the 17th level.