Denver is in a “Slight to Moderate” zone of termite risk. Although we don’t see too many structural problems related to termites in the Denver area, it can happen. I was recently at a home that was in need of repair due to age. During the repairs damage from termites was discovered. Luckily the damage had not caused a structural failure and the damaged wood posts and beams were already planned to be replaced with steel to improve floor performance.
It appeared that the termites entered the structure in two ways. One entry point was the wood columns bearing directly on the thin slab-on-grade floor. Through cracks in the concrete the termites could easily enter the wood column. The termites also entered the structure along the inside face of the brick foundation wall. They built mud tubes along the wall to protect themselves as they left the soil to the structure.
The mud tunnels may be difficult to see, but keep an eye open for a thin line of dirt no bigger than a pencil. Tunnels typically run along a wall or post, but they can sometimes stand alone as the termites build larger structures that can span over 18″ from the soil to the structure.
You can learn more about termites here: www.termiteinstitute.com