[5] The town sits in Nad Ali District of Helmand Province, southwest of the provincial capital Lashkar Gah.

Marjah is geographically situated in one of Afghanistan's major belts of poppy fields,[6] which are a source of funds for the Taliban.

[8] During the 1950s and 1960s the United States funded a scheme, run by the Helmand and Arghandab Valley Authority, to irrigate the fields around Marjah (Lashkar Gah/Helmand was nicknamed "Little America"), with many canals remaining to this day.

[1][7] In conjunction with this American-led development, which included building and staffing a number of local schools, the Afghan government jump-started a program in 1959 to resettle Pashtun nomads to the area, providing them each with "almost 15 acres of land, two oxen and free seeds", with a focus on growing wheat.

The rest of the year experienced little or no precipitation, and besides January, there was actually a consistent net loss of water through evaporation.