\[tab:results\] we list the results of the artificial KLF modeling analysis for the cluster samples in DR15. For each cluster we also include the number of Class I, Class II and Class III YSOs found in each population. The more embedded clusters DR15-C and DR15-W contain a population that according to our analysis, could have a mean age of 3.0 Myr. The populations flanking the main molecular pillar, DR15-SE and DR15-SW, appear to have mean ages as large as 3.5 and 4.5 Myr, respectively. The contour plots for these two samples, however, appear to have two local minima, suggesting age spreads as short as 3.0-3.5 Myr or as large as 4.5-5.0 Myr. The adjustment to an older age is in agreement with the less embedded status of these two samples. Notice that the confidence ranges in all cases indicate that our method cannot really constrain the age spreads satisfactorily (the 95 percent confidence range in DR15-C is the only one that suggest a constraint towards an age spread of 3.5 to 5 Myr). Still, given the embedded nature of these young star populations, we think it is little plausible that age spreads can be significantly larger than 5 Myr.

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