These towers are used in remote areas, normally on mountain tops with high elevation and a good view of the surrounding terrain, to spot smoke caused by a wildfire.
Once a possible fire is spotted, "Smoke Reports", or "Lookout Shots" are relayed to the local Emergency Communications Center (ECC), often by radio or phone.
[1] Part of the lookout's duties include taking weather readings and reporting the findings to the Emergency Communications Center throughout the day.
Often several lookouts will overlap in coverage areas and each will “cross” the same smoke, allowing the ECC to use triangulation from the radials to achieve an accurate location of the fire.
Some volunteer organizations in the United States have started to rebuild, restore and operate aging fire lookout towers.