Is the Trio in Trouble?

The three trunks of the Trio are all interconnected because they are part of the same tree! They were likely sprouts from a broken central tree, which makes them clones. The original rock matrix that buried the Trio in the late Eocene was excavated using dynamite by the Henderson family in the early 1920s. Metal bands were later placed around the stumps to secure loose pieces. However, small fragments and an occasional large chunk fall off the exposed stumps regularly! Will the Trio survive?

Monitoring Changes with Photogrammetry , How can Monument scientists monitor changes to the Trio due to weathering and gravitational slumping? Sensors on and around the stump record temperature and moisture levels, and staff observe the stump regularly for changes. However, in 2015, the Monument added a new tool to their monitoring efforts that lets them understand detailed changes to the shape of this Trio.

The science of photogrammetry involves measurements of real-world objects and terrain features from multipe photographs taken at various heights surrounding an object. A computer program assembles and fits the digital photographic data together into a detailed three-dimensional digital "shape." Monument scientists can then measure distances, heights, areas and volumes from a digital model. As this technique is employed every few years, changes to the shape of the Trio can be quantified and management strategies developed and tested.

[Photo captions, top to bottom, read] , . The Trio in the 1920s before the base of the stumps was uncovered and the Monument was established. The roofed shelter was added in 2001, but only partially protects the Trio from the elements.

. Photogrammetry field work was done in 2015 at the Trio and the Big Stump, above. A digital camera was used (red circle above) to take hundreds of photographs at various elevations surrounding the Big Stump.

[Black box in background photo caption reads] , This touchable Trio model was printed using the digital photogrammetric data collected in 2015. , [It appears that the model was removed to limit touching during the pandemic] . This historical marker was erected by National Park Service. It is Near Florissant in Teller County Colorado