There are several types of towers at Mesa Verde National Park, each with a purpose.
This is Rock Canyon Tower. I will first show you where it is (on the other side of Rock Canyon from where I am standing) using my amazing JohnBoy finger-pointing technology:
It was a watchtower or signalling tower, to watch for enemies or other threats and they were often built at strategic locations so messages could be relayed to people in other locations. There was also a small cliff dwelling on the hillside below the tower, perhaps to house the sentinels.
This is Cedar Tree Tower. It is on ground level, on the Chapin Mesa and is away from everything else and exposed to the elements. There is also a kiva (the ceremonial circle) next to the tower and a tunnel connecting the two. Kivas are often found next to towers.
Perhaps this was an outdoor “theater” where ceremonies or rituals were held. The tower may have been to elevate an authority figure and the tunnel may have allowed that person to get to the kiva without being seen.
And then there are fire towers. Almost 75% of Mesa Verde National Park has been affected by fire at one time or another. The largest, the Bircher Fire in 2000, destroyed over 22,000 acres. Thankfully most of the others were significantly smaller, each less than 5,000 acres. This was the area near Cedar Tree Tower:
And this is one of the three fire towers in the Park. There is a main tower at the highest point which is completely enclosed. My guess is that this open tower may only be used when there is a problem brewing on this side of the Park:
This is the main fire tower, located atop Park Point at 8,572 feet. It affords Park Rangers a 360 degree view of the area and has the necessary tools to calculate where a fire is, although modern GPS technology is probably put to use to provide a precise location once they know approximately where to send a ground crew or reconnaissance aircraft.