In 1920, Athabascans living upriver at Louden began moving to Galena to sell wood to steamboats and to work hauling freight for the mines. A school was established in Galena in the mid-1920s. In World War II a military air field was built adjacent to the civilian airport, and the two facilities shared the runway and flight line facilities. This air field was designated Galena Air Force Station shortly after the split of the United States Air Force from the United States Army, which occurred as a result of the National Security Act of 1947. During the 1950s, the construction of additional military facilities at Galena and the nearby Campion Air Force Station, in support of Galena's mission as a forward operating base under the auspices of the 5072nd Air Base Group, headquartered at Elmendorf Air Force Base, near Anchorage, provided improvements to the airport and the local infrastructure, causing economic growth for the area. Galena Air Force Station closed in 1993, following the end of the Cold War, but it remains in use effectively as a forward operating location that is used occasionally by the military. This use has recently come under scrutiny by the Base Realignment and Closure Committee
There were floods in 1945 and 1971. Because of the floods, a new townsite, called New Town, was chosen at Alexander Lake, about 2 1/2 km (1 1/2 miles) east of the original townsite. The city offices, the health clinic, schools, store, and more than 150 homes were constructed at New Town.
Galena has three schools. Galena City School is primarily for local K-12 students, and the vocational Galena Interior Learning Academy is a boarding school which draws students from around the state. The Galena boys' and girls' basketball teams were regional champions from 2004 to 2007. The boy's basketball team was state champion in 2008. Galena's third school is Interior Distance Education of Alaska, a state-wide homeschool support program that serves 3,500 students across the state. It is the biggest school (of any kind) in Alaska.
Galena is inaccessible by road, relying on river cargo in the brief summer for the bulk of its needs. This means the city must store large volumes of fuel oil. In 2004 Galena's City Council tentatively accepted a proposal from Toshiba Corporation to build the Galena Nuclear Power Plant, a small self-contained nuclear power plant. The demonstration plant, the prototype for a line which Toshiba hopes to sell to similar communities in the US and Canada, would (if built) be the first civilian nuclear plant in Alaska; Fort Greely, Alaska, had a small military SM-4 reactor until the early 1970s.
According to the United States Census Bureau, the city has a total area of 24.0 square miles (62.1 km²), of which, 17.9 square miles (46.3 km²) of it is land and 6.1 square miles (15.8 km²) of it (25.41%) is water.
There were 216 households out of which 49.1% had children under the age of 18 living with them, 50.5% were married couples living together, 12.0% had a female householder with no husband present, and 31.0% were non-families. 24.5% of all households were made up of individuals and 3.7% had someone living alone who was 65 years of age or older. The average household size was 2.83 and the average family size was 3.44.
In the city the population was spread out with 37.5% under the age of 18, 7.6% from 18 to 24, 29.9% from 25 to 44, 20.9% from 45 to 64, and 4.1% who were 65 years of age or older. The median age was 28 years. For every 100 females there were 121.3 males. For every 100 females age 18 and over, there were 123.3 males.
The median income for a household in the city was $61,125, and the median income for a family was $70,250. Males had a median income of $46,563 versus $37,000 for females. The per capita income for the city was $22,143. About 1.3% of families and 10.2% of the population were below the poverty line, including 1.4% of those under age 18 and none of those age 65 or over.
Galena is also mentioned in the film "War Games", as a point from which the US was to launch F-16s.