Americans have registered nearly half a million drones with the federal government, including more than 9,000 in Massachusetts.

Through a registration system launched late last year, the Federal Aviation Administration requires both hobbyists and commercial drone users to sign up.

The agency recently released data listing the number of drones registered in cities and towns across the country.The following maps show the number of recreational and commercial drones registered in each Massachusetts city and town.

As of the end of May, 461,120 recreational drones and 8,416 commercial-use drones had been registered with the FAA, according to agency records. More than 99 percent said they were United States residents when they registered; the rest said they lived in US territories or foreign countries.

AirMap, a Calif.-based company that offers real-time airspace information to drone operators and other stakeholders including airports, studied and mapped the FAA’s data on drone registrations.

“We’ve found that drones are where people are,” said AirMap co-founder Greg McNeal. “The data shows that most drone registrations take place in densely populated areas

According to McNeal, the data also highlights a challenge aviation regulators will have to grapple with.

“Tens of thousands of operators will be looking to fly in controlled airspace and in populated areas,” he said.

The FAA has been tracking reports of near-collisions between manned aircraft and drones, and working to establish new rules and guidelines to prevent crashes

There have been dozens of sightings of drones by aircraft pilots in Massachusetts. Last week, the crew of a United Airlines flight traveling from Boston to Chicago spotted one about 10 miles northeast of the airport, the FAA said.

The above heat map, provided by AirMap, shows the number of drones registered for recreational use around the United States.

The above heat map, provided by AirMap, shows the number of drones registered for commercial use around the United States.

Matt Rocheleau can be reached at matthew.rocheleau@globe.com. Follow him on Twitter @mrochele