Wildfire is a constant danger in places with vegetation. Shortly after we crossed the border into Alaska, we started to notice smoke off in the distance. Soon we could smell it. Then we came to this sign warning of 'Wildfire Ahead'! We never saw the actual fire this time, although on previous trips we had been stopped along the highway as fire was too close to the road.
As we drove through some old fire areas from previous years the progression of growth caused by the fires was obvious. When the spruce trees burned, the new growth coming up was all birch and other deciduous trees. As they matured, they provided a place for new spruce trees to sprout and flourish. As the spruce trees matured, they choked out the other trees. When another wildfire came along and burned the spruce, the cycle started again.