Between 1912 and 1916 Blanding received an infusion of new blood because of political unrest in Mexico. Many Mormon families, who had previously fled south of the border during the intense anti-polygamy persecution of the 1870s and 1880s, abandoned their Mexican homes and moved back to the United States. Some found refuge in San Juan County. In January 1914 the town could claim a population of 500 people; five years later it had risen to 1,100. Not all of this growth was attributable to events in Mexico, but a sufficient amount of immigration occurred to create in the minds of at least some of the early settlers a slight division between them and the newcomers, called "Pachecoites."

During this same era, modern conveniences started to become a part of the town's life. Schools moved from tents with sideboards to a frame building in 1908. A year later, a phone line stretched from Blanding to Monticello, connecting residents to Moab and the outside world. Electricity arrived on a part-time basis in April 1918 and became a full-time reality in 1935. Improvement and maintenance of the water system remained an ongoing task. In 1916 the town constructed a reservoir with a distribution system comprised of wooden pipes that frequently had to be replaced. By 1921 work had started on a 5,400-foot tunnel on top of the mountain to bring excess water from its north side. Thirty-one years later, at a cost of $125,000 and a great amount of hard work, the townspeople completed the tunnel and watched the precious water flow into the reservoirs below.