In the western American state of Utah,drone aircraft are flying near avalanchesto watch snow crashing down from mountains.Drones are also being used in the southeastern United States.For example, in North Carolina,they are searching for endangered birdsand the places they use to raise their young.Public transportation agencies are using drones in nearly every state.That information comes the American Associationof State Highway and Transportation Officials, or AASHTO.In a report released this month, the nonprofit groupfound a large increase in the use of drones over the past few years.The aircraft are also called unmanned aerial vehicles.The association's survey found that governmentsas well as private citizens have accepted the technology.They include individuals who love flying model aircraft.In 2016, the group found that no state transportation agencywas using drones every day.Now, 36 states employ certified drone pilots.Jim Tymon is the executive director of the association."You've seen the cost of drones come down significantly,and the capabilities that come along with some dronesincrease significantly as well," he said.Jared Esselman is the director of aeronautics at the Utah Department of Transportation.He says that drones are valuable for all kinds of work."We can predict not only snow slides,but mudslides and water runoff as the snow melts," Esselman said."Drones are a perfect tool for any job that is dangerous or dirty."In North Carolina, drones are finding the nests of endangered specieslike the red-cockaded woodpecker, reports Basil Yap.He is the unmanned aerial systems program managerat the state's transportation department.People once used helicopters or all-terrain vehiclesto inspect for evidence of woodpeckers before building new projects.But the drones can do the job quicker with fewer problems, Yap said.A number of states are beginning to explore how to create lawsto control a flood of private drone traffic that is likely to come in the future.In Ohio, the state government is workingon an air-traffic control system, called SkyVision,which would enable drones to recognize and avoid other aircraft in flight.