[5] The county terrain consists of semi-arid rolling hills, partly devoted to agriculture.

The Missouri River flows southeastward at its SW corner, and delineates a portion of the county's south boundary line.

Its highest point is on the lower part of its eastern boundary line, at 2,080 ft (630 m) ASL.

[8] As of the 2020 census, there were 1,262 people, 522 households, and 355 families residing in the county.

Hyde County voters have been reliably Republican ever since South Dakota's statehood.

In only two national elections – the Democratic landslides of Franklin D. Roosevelt in 1932 and Lyndon B. Johnson in 1964 – has the county ever voted for a Democratic presidential candidate – although in the Republican landslides of 1956 (due to a major drought and resultant agricultural problems) and 1972 (due to a strong “favorite son” vote for George McGovern) the county actually voted about 4 points more Democratic than the nation at-large.