It is probable that people will continue to deface and destroy these images. As a means of preservation, removal is impractical. The most practical means available to preserving these images is to photograph them. High quality photographs of these images may be all that we can look at someday. Even before the rock faces are destroyed, photos can yeild some intriguing information.

What we do here is to apply some basic imaging techniques to photos of the rock face at Atl Atl Rock to try to answer a single question.

The Question - Are these images contemporaneous?
The 'contemporaneousness' of all the images is an important question because it influences the answers to other questions such as, were all these images made by the same person, or group? 

It is suggested by looking at all the examples of each type of image (see classification) that a different hand created them each. In some cases the only way to be certain of differences in age would be to test the degree of 'patination' on the surface of the ethed part of each image. If the degree of patination would vary, ostensibly, the age of the images would also be different.

The Hypothesis - The images were made at different times.
According to Whitley, some of the images appear to have stylistic differences. We note this when comparing the images of the feet. Whitley also observes that the images do not all appear to have been made at the same time. (1) 

What does the other evidence suggest?
The differences in the coloration of the etch marks were not what Whitley was referring to what he went out on the limb and stated that ' .. it is also likely that some of the engravings at this site were made both earlier and more recently.' (2) This statement was in reference to the Atl Alt's depicted here. According to Whitley, the introduction of the bow and arrow displaced the Atl Atl as a hunting implement in this area. He estimates that date to be around 1500 BP. He infers that the images here must be at least 1500 years old. The notion that bows and arrows automatically replaced the Atl Atl seems to have an evolutionist bias to it. 

How old are the petroglphs likely to be?
Whether or not the Atl Atl was completely abandoned with the introduction of the bow and arrow is really just a matter of opinion. Perhaps the Atl Atl was used primarily for large game. As a tool, the Atl Atl is unsuitable for some of the smaller game that exists in the area. The bow and arrow no doubt made the smaller game that is likely to congregated at the Muddy and Virgin Rivers more accessible.

With a pragmatists bias we would like to think that the bow and arrow was an addition to the hunters tool kit, not a replacement or displacement of one tool over another. Which tool was used depended on the game sought.

This perspective seems to be born out by the facts. Mark Harrington's excavations at Lost City in the nearby Muddy River Valley revealed point types which, due to their size were likely to be Atl Atl points. Plates 66 and 67 show points of varying sizes. In chapter 6, 'Description Of Artifacts', it is unclear which points Shutler is specifically referring to in Group " I " projectile points because he refers to points with and 3 without provenance in this group, where these dimensions are listed:

Group " K " and Group " P " have projectile points in excess of 5 cm.

Unfortunately, as Shutler remarked, "Of the countless wood artifacts recovered ... only a few were located to study". This gives us an incomplete sample of the wood artifacts and thus we have to guess that there should have been shafts large enough to carry the points that were found in the houses at Lost City.

These points were found in a context which puts them in a 1300 to 900 BP (700 to 1100 AD) time window. Well after the 1500 BP (500 AD) time threshold. Thus there is no practical reason to attribute any of the images to any specific time. At least we should hope that the hunters in this area were practical enough to realize that each tool has its own use. Using the 'These are ultimately practical people' approach, we would like to think that the use of the Atl Atl waned because the type of game that it was used to hunt either either declined in population or fell out of favor for some reason.

The Criteria - What constitutes a 'positive'?
That some of the images have a slightly different color seems to be the case when you look at the images. Some images, particularly the 'sheep' icons seem to be a shade lighter than the other images around them. This contrast between the shades of red in the etched portion of one image with another image is what implies a difference in age between these images.

The Method - Digital Imaging
Since we cannot test the entire etched surface, we can do almost the same by manipulating the color of the image. This is a new and untried technique. While there may be skeptics, they will only be those who did not bother to look at the evidence. The quality of the digital images and the imaging procedures make the inferences transparent.

Digital Photos
The photos of Atl Atl Rock were taken at optimal distance, angle and lighting to show all the images as evenly as possible. The camera is a Fuji FinePix 620Z which records images at 6.1 mega pixels. This results in a huge image of 2832 by 2128 pixels. This translates to a clear image which is 39.3 by 29.56 inches if printed. This is far beyond the capacity of the average digital camera in both the amount and quality of the digital data.

The photos when viewed at full size put the image only a few inches away from the viewer.

Digital Imaging
Some of the digital imaging procedures that were used to elucidate differences in the color quality of the images by:
1) changing the quality of the colors together, and separating red, blue and green colors;
2) varying the brightness and darkness;
3) varying the hue and saturaturation;
4) removing the color and varing the greys;
5) inverting the images colors;
6) removing colors; and many other techniques as they are needed.

Imaging Software
We did not have to look far for a superior imaging product. We have used Adobe Photoshop to manipute images since 1997 and skill with this particular tool is considered advantages. While other products such as Photo Impact and Paint Shop were briefly considered, we feel that the predominance of the Adobe product made it a natural choice. The results that we obtain here and the procedures that we used to get them are easily to duplicate because Adobe Photoshop is such a well known and highly regard photo imaging software.

The only barrier in this replication is the high level of skill usually required to use Photoshop. And it's cost.

To partially alleviate this, each step in the imaging process is noted.

Conclusions:
So far it appears that image extraction does distinguish and articulate the differences in the color shading of the etch marks. This in turn allows us to determine if the etch marks are contemporaneous.

Preliminary results indicate that there are three different times for image construction or reconstruction. First the main image was created. Then the 'cross' was etched. The third set of etchings include the three sheep in the middle, the 'shaman' images and the lower rope ladder image. It appears that  these images were either added last or were retraced last.