The Federal Aviation Administration, which is moving toward a 2015 target for opening the skies for public and private drone use, estimates that more than 30,000 could be in flight nationwide by 2020.
''We're not darkening the sky yet, but we're poised," Richard Christiansen, vice president of aerospace engineering firm Sierra Lobo Inc., said recently at a Southern California symposium on civilian drone uses.
At stake for each state is a piece of $82 billion in economic activity the drone industry estimates it will generate between 2015 and 2025.
But the emerging technology has attracted questions about use, safety and privacy, leading state and federal regulators to grapple with how to govern drones.
Unmanned systems are most commonly used by the military, which has increased its reliance on drones to conduct surveillance and track down terrorists in Afghanistan and Pakistan. But advances in technology and cuts to defense spending have led manufacturers to experiment with new ways to use what the industry calls "UAVs."
Boosters of the technology say it could be used to assess and sell real estate, help news organizations report stories and patrol oil pipelines, ports or vast swaths of water off the coast.
First responders and emergency management officials see potential in monitoring and fighting wildfires or assessing damage from natural disasters in real time. Some law enforcement officials want to use drones to conduct surveillance and search-and-rescue operations or crack down on illegal drug cultivation and trafficking.
Shipping companies have explored using them to deliver packages, industry representatives say.
''Everywhere I go people ask me for new applications for these things," Kristen Helsel, a vice president for Public Safety UAVs at AeroVironment, told industry representatives and policy specialists at the symposium. "There are smart people out there who when we put the technology in their hands, they're going to be able to think of great ways to use it that will save lives and protect property."
But the opportunity for expansion has sparked privacy concerns and calls for rules about where, how and by whom the system can be used.
''The key thing is that there has to be a (regulatory) framework in place before the drone is deployed," said Linda Lye, a staff attorney with the American Civil Liberties Union of Northern California. "In too many other instances, we see the technology rapidly outpacing the law."
The ACLU wants states and federal officials to ensure information collected in non-law enforcement capacities, such as surveying a forest, isn't stored and later used for other purposes. The organization believes a regulatory scheme must include warrant requirements and other safeguards in place to protect the rights of citizens.
It is especially concerned about how police and other government agencies will deploy drones. Such uses, Lye believes, will be widespread because the aircraft are less costly than helicopters or other surveillance tools and the Department of Homeland Security is offering grants to help pay for the equipment.
Industry reports downplay those uses, saying agriculture is expected to attract much of the spending in the early years.
The FAA says 50 applications have been received from 37 states.
Hobbyists like Jason Goldman, a recent Pepperdine University graduate who builds his own drones, are already in the air for recreational purposes, awaiting the OK to do more with their drones.
''We're here now and we're ready," Goldman told the symposium audience last week. "I say let us fly."