Montero is a city and a municipality in Santa Cruz, Bolivia, about 50 km north of Santa Cruz de la Sierra. Montero had a population of 137,93…Montero is a city and a municipality in Santa Cruz, Bolivia, about 50 km north of Santa Cruz de la Sierra. Montero had a population of 137,931 as of 2020 and has experienced growth in recent decades, becoming an important city in the region.