The promise of tens of thousands of jobs has U.S. states jockeying to become hosts for testing before drones are introduced alongside civil aviation in U.S. airspace.

A vast network of unmanned aircraft manufacturers, marketeers and promoters that descended on Washington for a conference pressed home a point made in a March report: Growth in civilian drones can create up to 100,000 jobs nationwide.

States that encourage drone testing on their soil stand to gain more jobs than states that remain skeptical about the new technology, drone promoters say.

As excitement over drone-related job prospects grows, the industry has gone to great lengths to separate -- in public consciousness -- civilian craft from the military types that provoked controversy, debate and protests.

Protesters from the Code Pink anti-war group used pink mock-drones to protest outside the venue of a mid-August conference of the Association of Unmanned Vehicle Systems International.

AUVSI is rated the largest lobby group supporting promotion of unmanned aircraft, which it insists shouldn't be called drones.

AUVSI's annual gathering at the Washington Convention Center brought together about 8,000 participants from 40 different countries. Most delegates said they were focused on generating new business from unmanned technology systems, promoting diverse use on farms, firefighting and law enforcement, security and surveillance.

The industry got a huge boost when the Federal Aviation Administration said last year it would allow drones to join civilian airspace once a regulatory framework was in place.

Up to 10,000 unmanned craft could be flying in U.S. airspace within five years. The FAA wants to ensure that drones keep a safe distance from manned civilian airliners and other piloted aircraft.

More drones are likely to take on duties on farms and orchards, river and coastal areas and law-enforcement from small towns to cities. Private companies are likely to be allowed to fly or rent their own drones, in some cases replacing manned services such as couriers.

There will be jobs galore before that happens, AUVSI says.

By 2015, when commercial drones are set to enter U.S. skies on a comprehensive scale, the first tens of thousands of about 100,000 jobs to be created over 10 years will be there for grabs.

The AUVSI report says the industry will add $13.7 billion to the U.S. economy.

"While there are multiple uses for UAS in the [national airspace system], this research concludes that precision agriculture and public safety are the most promising commercial and civil markets," the report says. "These two markets are thought to comprise approximately 90 percent of the known potential markets for UAS."

The report says tax earnings for the states that host test sites for the drones of the future will exceed $635 billion in 2015-2025 -- the first 11 years following integration.

The FAA is set to select six locations as UAS test sites. States across the United States were present at the AUVSI conference to lobby support for their selection as hosts for the test sites.