Walter Mondale, Vice-President of the United States under Jimmy Carter (1977-1981) and the Democratic party nominee for President in 1980, attended Heron Lake Public High School and lived in the Methodist Episcopal Church parsonage (still present in the town) for three years prior to 1946. His father was minister at the church during that time. Many residents of the town from that time have tales of the young Mondale's shenanigans. The local electorate voted overwhelmingly against Mondale in the 1980 election.
Inkpaduta, a Mdewakanton Sioux Indian leader in the area from the 1850s until his departure to join Sitting Bull's band in Manitoba and Saskatchewan, camped at Heron Lake both before and after his participation in the Spirit Lake massacre and Dakota War of 1862, also known as the Sioux uprising.
Several residents at the time claimed to have seen Al Capone in the town at one point during Prohibition. The town was on the route from the Twin Cities to Sioux City at the time, so the reports are intriguingly plausible if not substantiated.
Mike Calhoun claimed to have seen the Monkeemobile pass through town in 1967 or 1968, but it seems more like the imaginative fantasy of a smalltown boy where nothing important ever happens than a credible report.
Minnesota State Highway 60 serves as a main route in the community.
There were 285 households out of which 32.6% had children under the age of 18 living with them, 51.9% were married couples living together, 6.3% had a female householder with no husband present, and 38.9% were non-families. 34.4% of all households were made up of individuals and 17.2% had someone living alone who was 65 years of age or older. The average household size was 2.52 and the average family size was 3.30.
In the city the population was spread out with 26.7% under the age of 18, 7.6% from 18 to 24, 25.4% from 25 to 44, 15.9% from 45 to 64, and 24.5% who were 65 years of age or older. The median age was 39 years. For every 100 females there were 97.9 males. For every 100 females age 18 and over, there were 97.5 males.
The median income for a household in the city was $32,222, and the median income for a family was $40,625. Males had a median income of $28,958 versus $19,219 for females. The per capita income for the city was $15,657.