The National Rifle Association and New York Mayor Michael Bloomberg lined up on opposite sides of the recalls.
Reported contributions to Morse and Giron totaled about $3 million, dwarfing the amount raised by gun activists who petitioned for the recall, though some independent groups didn't have to report spending. Both the NRA and Bloomberg contributed more than $300,000 to the pro- and anti-recall campaigns.
"The people of Colorado Springs sent a clear message to the Senate leader that his primary job was to defend their rights and freedoms and that he is ultimately accountable to them - his constituents, and not to the dollars or social engineering agendas of anti-gun billionaires," the NRA said in a prepared statement.
Most voters had to cast their ballots in person.
"This is a good, old-fashioned knock and drag operation — knocking on doors and dragging them to the polls," said Colorado Democratic Party chairman Rick Palacio, who worked Giron's district on Tuesday.
Hickenlooper initially rejected calls for stronger gun control laws after 12 people were killed and 70 injured in an Aurora movie theater in July 2012. The governor changed his mind right before the December 2012 Newtown massacre, in which a gunman killed 20 children and six women at Sandy Hook Elementary School.
Hickenlooper, who is up for re-election in 2014, kept a low profile in the recalls. A recent statewide poll by Quinnipiac University suggested that 52 percent of voters disapproved of his gun policy while only 35 percent approved.