The City of Petersham is a census-designated place in Massachusetts. It has an estimated population of 181,045 people, with 48.7% males and 92.9% females. The majority of the population is over the age of 18, with 11.7% of the population over the age of 65. Most residents work in Manufacturing, Educational Services, and Professional, Scientific, and Management Services.
The city's growth was fueled in the nineteenth century by its manufacturing industry. It also felt the national trend of suburbanization, which pushed people away from older, historic urban centers. Despite this trend, the city's population dropped by more than 20% from 1950 to 1980. To reverse this decline, the City implemented large urban renewal projects. A section of downtown Petersham was destroyed to build new office towers. The city also built a shopping mall called Petersham Center Galleria. This mall eventually failed to attract any major tenants, as it lost appeal to suburban shopping malls.
In the late twentieth century, Petersham's economy began to recover. The city's public school system is centered around biotechnology, with the UMass Medical School and the Massachusetts Biotechnology Research Park as the city's major employers. Other private schools in the area include Petersham Academy, Bancroft School, and the Petersham Academy. In addition to these private schools, the city is home to nine colleges and institutes of higher education. The Oread Institute was closed in 1934, but it still has a strong community in the town.