Previous Dendrochronological Research in the Area

Dendrochronology in eastern Utah has also been practiced for more than 60 years, but with mixed results. Unpublished archaeological “reconnaissance” projects by Albert Reagan, L. L. Leh, and J.O. Brew in the 1930s collected specimens from sites in the Nine-Mile Canyon and Range Creek areas that were sent to A.E. Douglas (LTRR site file notes). Six samples, two of which later yielded dates, were also submitted to Emil W. Haury at Gila Pueblo, but the context of their collection is unknown.

In 1946, Edmund Schulman expanded his interest in old-age conifers and the Colorado River Basin to northeastern Utah. He was particularly attracted to the area because of the sample submitted by Reagan’s photographer, Leo Thorne. “It was this specimen which excited the writer’s curiosity .. and led eventually to the analysis …” (Schulman 1948:4). Schulman collected living tree samples from Nine-Mile Canyon in 1947 and 1948 and actively sought the collaboration of archaeologists to extend his chronology using archaeological samples. Using samples from several living tree and archaeological sites, he was quickly able to extend his chronology by almost 800 years to AD 397 (Schulman 1948). Unfortunately, Schulman’s interests shifted to the bristlecone pines of California (Schulman 1954), and his untimely death in 1958 prevented further research in northeast Utah.

Table 1 lists the living pinyon and Douglas-fir chronologies for northeast Utah and northwest Colorado contained in the International Tree-Ring Data Bank (ITRDB) and elsewhere. Interestingly, when Schulman’s chronology was submitted to the ITRDB, it was only extended to AD 1201, presumably because the AD 396-1200 period did not include enough samples to meet ITRDB standards. The Schulman (1948) chronologies, however, are the published master skeleton plots and indices on file at the LTRR.

Table 1. Living tree chronologies form northeastern Utah.

Nine Mile Canyon D-fir 1920 1201 1949 Schulman (ITRDB)
Nine Mile Canyon High D-fir 1920 1194 1964 Stokes and Harlan (ITRDB)
Nine Mile A D-fir 2400 1186 1947 Schulman 1948
NIne MIle B D-fir 2300 1236 1947 Schulman 1948
Nine MIle C D-fir 2130 1240 1947 Schulman 1948
Sunnyside D-fir 2350 1225 1947 Schulman 1948
Nine Mile Arch Combined D-fir n/a 397 1947 Schulman 1948
Minnie Maud Pinyon 2250 1215 1978 LTRR Site files
Plug Hat Rock Pinyon 2150 1241 1978 LTRR Site files
Uinta Mtns B D-fir 2289 1730 1971 Harsha et al. (ITRDB)
Uinta Mtns C D-fir 2289 1635 1971 Harsha et al. (ITRDB)
Uinta Mtns D Pinyon 2289 1423 1971 Harsha et al. (ITRDB)
Wells Draw Pinyon 2100 887 2001 Gray et al. 2004
Nutter's Ridge Pinyon 2200 1040 2001 Gray et al. 2004
Dutch John Mtn Pinyon 2150 1365 2001 Gray et al. 2004
Red Pine Canyon Pinyon 2300 1405 2001 Gray et al. 2004

Gray et al. (2004) used pinyon pines to develop a precipitation reconstruction for the Uinta Basin from AD 1226-2001. Interestingly, they did not exploit Schulman’s earlier research; thus their chronology is shorter than even Schulman’s ITRDB chronology, and 800 years shorter than his actual chronology. Their efforts are important, however, because they will provide a second, completely independent chronology and precipitation reconstruction for the area.

After Schulman’s efforts, dendroarchaeology in northeast Utah languished for almost five decades. In 1984, the Midwest Archaeological Center conducted excavations in a small rockshelter (42 UN 1103) in Dinosaur National Monument. The eight samples submitted, all pinyon, yielded seven dates ranging from 1291p-1682vv (LTRR site files), but are not related to the Fremont occupation of the area. In 1987, Abajo Archaeology submitted 12 samples, of which four produced dates ranging from 1046p-1156+r (Table 2).

Table 2 lists the tree-ring dates from Fremont occupations in northeastern Utah; the 50+ undated samples are not included in the table. The most notable aspect of the dates is that the dated species are all Douglas-fir. This species distribution clearly reflects the selection processes of dendrochronologists, not prehistoric Fremont people. It also reflects Schulman’s development of a Douglas-fir chronology. The development of long pinyon, and possibly juniper, chronologies will aid in dating previously collected samples of those species. A second important aspect of the dates is the preponderance of noncutting (vv) dates. Noncutting dates indicate the removal of outside rings from a sample, either by natural or cultural processes (Ahlstrom 1985; Dean 1978). In this particular case, we suspect that many of these rings were accidentally removed during collection and transport to the LTRR.

Table 2. Fremont archaeological tree-ring dates.

42 EM 2095 UKM-19 D-fir 1102p 1155vv
UKM-20 D-fir 1046p 1150v comp
UKM-21 D-fir 1112p 1156+r comp
UKM-24 D-fir 1109p 1149r comp
Long Mesa Ruin HLL-1 D-fir 798p 979+vv
HLL-2 D-fir 886p 1013vv
HLL-3 D-fir 850p 1000vv
HLL-4 D-fir 911p 1073v inc
HLL-5 D-fir 981p 1084r inc
F-2227 D-fir 851p 1003vv
F-2230 D-fir 854p 979+vv
Hill Canyon Ruin HLL-7 D-fir 926p 1001v inc
42 DC 534 NNM-40 D-fir 836p 1062vv
Four Name House NNM-24 D-fir 1019p 1152rB comp
NNM-27 D-fir 815p 997++vv
Four Name Annex NNM-35-2 D-fir 746fp 784vv
Upper Sky House NNM-33 D-fir 836p 1051+vv
NNM-34-1 D-fir 899p 1090vv
NNM-34-2 D-fir 930fp 1033vv
NNM-34-3 D-fir 1010p 1088vv
NNM-34-4 D-fir 882fp 1089vv
NNM-34-5 D-fir 918p 1053vv
NNM-34-6 D-fir 833fp 1033++vv
NNM-34-7 D-fir 816p 892vv
Lookout House GP-5931 D-fir 805p 1143++LGB inc
Sky House NNM-5 D-fir 894p 1090v inc
NNM-6 D-fir 725p 1059+vv
NNM-7 D-fir 937p 1061rLG comp
NNM-8 D-fir 396p 769+vv
NNM-9 D-fir 760np 983vv
NNM-10 D-fir 815p 1089vv
NNM-15 D-fir 992p 1090vv
NNM-17 D-fir 849p 1089v inc
NNM-18 D-fir 995p 1088vv
NNM-20 D-fir 848fp 931vv
NNM-21 D-fir 898p 1088vv
NNM-22 D-fir 1011p 1079vv
NNM-23 D-fir 816p 1027+vv
GP-5910 D-fir 837p 1012+vv
GP-5936 D-fir 937p 1093vv
Olger Ranch Ruin NNM-28 D-fir 931p 1065cLB inc

Finally, the distribution of the few available cutting dates, suggests Fremont site use in the AD 1000s, 1040s, 1050s, 1060s, 1070s, 1080s, 1090s, 1140s, and 1150s. This distribution suggests an episodic Fremont occupation in the early and late 11th century, a reoccupation in the mid-12th century, and abandonment before AD 1200 and is similar to the inferrences of Talbot and Wilde (1989), which have been disputed by Massimino and Metcalfe (1999). A greater number of dates, cutting dates, and dated sites will allow us to examine the Fremont “episodic occupation” hypothesis in terms of mobility and storage strategies and will have implcations for other Fremont areas. Perhaps it is simply a function of few real data points. In addition, a well-developed quantitative precipitation reconstruction will allow us to relate these behaviors to climatic variation.