Northern Great Basin Prehistory Project
Archaeological Field School
2017 Summer Session

Introduction to Connley Caves Research

Connley Caves, Cave 5
Connley Caves, Cave 5

Stephen Bedwell and a crew of University of Oregon graduate students excavated at the Connley Caves (35LK50) in the Fort Rock Basin during the summers of 1967 and 1968 (Bedwell 1970). While Bedwell drew on the data collected from many sites, none have remained as pivotal to our understanding of human response to changing paleoclimate and ecology in the Northern Great Basin as the archaeology at the Connley Caves.

For the last three decades researchers have cited Bedwell's doctoral dissertation (1970) and post-mortem publication (1973), even though they suspected there were serious problems with the data (cf. Grayson 1979, 1993 for examples). The main reasons for citing his work were the large numbers of radiocarbon dates and diagnostic materials recovered from the 3-4 meters of stratified cultural deposits at this site. Few other sites in the Northern Great Basin, other than the Paisley Caves, have produced such an impressive and widely-cited archaeological record. However, Bedwell's interpretations of the Connley Caves has sparked vigorous debate about the importance of wetlands resources to Early Holocene occupants of the Great Basin. Most importantly, the validity of his radiocarbon dates, paleoecological-climatic reconstructions, and species identifications have been questioned and sometimes proven spurious (cf. Grayson 1979). Consequently, it was imperative to reinvestigate the Connley Caves.

Our research goals for the reinvestigation of the Connley Caves are to provide more carefully controlled excavations and more reliable analysis of the archaeological and natural samples available at the site. In 2000 and 2001 we began reevaluation of the site. In 2002 we began work at the Paisley Caves, and now, beginning in 2014 and annually since we have taken what we learned at the Paisley Caves and are applying stronger integrative theory and investigative techniques to resolve the issues resulting from Bedwell's research.

UO Field School Excavations at the Connley Caves: 2000-2001 and 2014-Present

Bedwell's research, in both the field excavations and laboratory analysis, suffered from a lack of close attention to detail. His crew’s field notes clearly indicate Bedwell’s disdain for personal involvement in the excavations. He preferred to leave the excavations and documentation to his crew while he mapped the sites and looked for new sites throughout the basin. For their part, the crew also preferred to have him out of the picture (Bussey and Rohrbaugh, personal communications). This lack of personal 'hands-on' field experience at the site meant that Bedwell never fully appreciated the complexity of site formation processes operating there. In the laboratory, Bedwell uncritically accepted species identifications, radiocarbon dates, and artifact associations (see Grayson 1979 for a more complete discussion). In any new investigation then we must begin with an accurate understanding of the natural and cultural site formation processes affecting the archaeological deposits of the caves. It is absolutely the single most vital issue of an adequate assessment of the site. Consequently, we approach the re-excavation and analysis of the Connley Caves with extreme caution, careful planning and close supervision and interactive-teaching of all students in all phases of investigations.

2000 Field Investigations. The 2000 investigations at the site began with the excavation of a backhoe stratigraphy control trench in front of Cave 5 where Bedwell had previously placed a backhoe 'test hole'. The manual excavations at the Connley Caves were then conducted in arbitrary five centimeter levels, following natural stratigraphy as much as possible. Excavated soil was passed through eighth-inch wire mesh and all cultural materials were recovered. Column samples of sediments 10x10x10 cm (1-2 liters) were taken from unit walls which appeared representative of the deposits in each cave. Additional soil samples were taken as new strata and cultural features were encountered. Ecofacts, including rounded beach gravels, botanical samples, and modern faunal remains from the surface of Cave 5, were collected for later study.

Manual excavations in front of Cave 5 began with three conjoined 1x2 meter excavation units forming a trench six meters long on a north-south axis. The head of this trench was located one meter east of the backhoe trench (actually between Cave 5 and Cave 4 in a sheltered area) and roughly two meters south of the cliff face. The manually excavated trench cut through six natural and cultural strata to reach a maximum depth of 310 cm. Small and large corner notched points were recovered to a depth of about one meter in these excavations. Very few tools and no projectile points were recovered from one meter to the Mazama tephra deposits directly above the paleosol. Cascade type foliate points were recovered below the Mazama tephra at about two meters. Below that were Western Stemmed and lanceolate points.

2001 Field Investigations. The bottoms of excavation units in Cave 5 were lined with plastic at the end of the 2000 field season and then backfilled by a backhoe. The 2001 field season began with the manual removal of backfill from units 1, 2, and 3 and the 2000 backhoe trench in front of Cave 5. Excavation of the one meter wide bulk between the manual and backhoe trenches in Cave 5 involved one 1x1 m (#9) and two 1x2 meter (#s 10 and 11) units. This resulted in the excavation of a roughly three meter by five meter block, the western third of which was an access ramp maintained through the south end of the reopened 2000 backhoe trench.

A 2x2 m excavation unit (#15) was attached to the north end of this block to remove extremely loose deposits between the cliff face and the north end of the 2000 manually excavated trench. Excavation of Unit 15 proceeded in 10 cm levels through the extremely dusty and acrid smelling sediments of what appears to have been a large rat midden and garbage dump containing thick bundles of grass, juniper bark, sagebrush, bulrush stalks, basket fragments, bulrush matting and bag fragments, cordage, twine, and human feces. Associated Elko and Rose Spring type projectile points suggest that these materials date from the Late to possibly Middle Holocene period, i.e. historic to ca. 5000 BP. Excavations were terminated near the bottom of the Mazama tephra at 160 cm in this unit. All perishable materials were recovered in the loose, dry, coarse grained deposits above 140 cm. Below 140 cm were mixed tephra and silty-sandy sediments too moist to preserve perishable artifacts.

2014-2016 Field Investigations. In 2014, a 2 x 4 meter excavation block was established at the mouth of Cave 4 on an east-west axis adjacent to the south wall of Bedwell’s Unit 4A. Our interests were to determine what had caused the inversion of Bedwell’s 10,600±190 (Level 38) and 11,200±200 BP (Level 32) radiocarbon dates in Cave 4 and to accurately date the oldest deposits in this cave. Bedwell did not refill the pits left by his 1968 excavations. Consequently, we spent the summer of 2014 doing ‘the archaeology of archaeology’, digging through Bedwell’s redeposited backdirt as evidenced most acutely by alluvially redeposited sediments containing 1960s era plastic photography flashbulbs, cigarette filters, and other junk. We finished the season in or just below the thick deposit of Mount Mazama tephra.

Gratefully, the 2015 season was spent digging less disturbed sediments below the stark white primary deposit of Mount Mazama tephra. By the end of the session, we had reached Lithostratigraphic Unit 1 (LU1), the water rounded cobbles and gravel of Pleistocene Fort Rock lake beach deposits, some 300 centimeters below the modern surface. Abruptly overlying LU1 was LU2, a 20 to 25 centimeter thick, compact, yellowish-orange brown silty sediment including 30% or more angular to rounded gravel and cobbles. The yellowish-orange color suggests oxidation of iron due to submersion or saturation of the stratum by groundwater. Above this, LU3 was a dark brown sandy silt with laminae and pockets of angular to sub-angular gravels. Grains of white Mount Mazama tephra in LU3, intruded from overlying LU4, allow the tracking of most rodent and human disturbances penetrating from above this stratum. Horizontally, dense concentrations of artifacts were encountered along the east side of the cave. Cultural deposits dip toward the west wall where alluvially-sorted silts filled a depression that may have been a pit of some kind dug by LP/EH inhabitants in that area. Intrusive Mount Mazama ash surrounds the bases of massive boulders well below the primary tephra lens in this area. This suggests that the roof fall occurred sometime shortly before the 7600 year old climactic eruption of Mount Mazama, allowing unweathered primary ash fall to fill voids around the rock. The roof fall appears to have literally “splashed” earlier cultural deposits outward from the massive boulder intrusions into LP/EH sediments. If the depression nearby is cultural, as suggested by the correlation of its upper boundary with a major concentration of artifacts, inhabitants dug through older artifact laden deposits and scattered the spoil dirt over the middle and east side of the cave surface. Thus, there is clear evidence of significant redistribution of LP/EH deposits across the floor of the cave.

Vertically, there is a major concentration of stone tools and lithic debitage in LU3, underlain by a minor concentration some 25 centimeters below it. A slight increase in cultural debris at the LU2-LU3 contact is most likely due to settling of small artifacts through the deposits to the compact upper surface of LU2. While an occupation earlier than 13,000 years cannot be positively ruled out, since the Western Stemmed point found at greatest depth also has the thickest obsidian hydration rind of 10.8 microns, dating of charcoal from the LU2-LU3 interface has so far only produced 13,000 year old ages common to overlying stratum LU3.

The 2016 field season was spent cleaning out the redeposited sediments filling the interior of Cave 4. These had been washed and blown back into the cave from the huge pile of spoil dirt Bedwell left at the mouth of the cave. While only a single 2 x 2 meter excavation unit actually cut into undisturbed deposits below Bedwell’s units 4A and 4B, the cave was well “prepped” for major excavations to be conducted in 2017.

Finally, major excavations reopened the north end of the 2001 excavation block along the cliff face between caves 4 and 5. A small rock overhang was partially cleaned out down to the volcanic ash layer. Minimal excavations below this ash recovered foliate projectile points and dense deposits of lithic debitage and bone. This area is prepared for exciting and undoubtedly highly productive excavations below thick deposits of undisturbed Mt. Mazama tephra.

Site Chronology


A single fragment of Artemisia charcoal dated to 9950 cal. BP, clearly out of stratigraphic sequence, was obtained from Pleistocene basal unit LU1 in 2015. The remaining nine, single fragment, species-identified charcoal samples that year were recovered from cultural deposits in LU3 and at the LU2-LU3 interface. Samples of Artemisia, Pinus, and Salix produced radiocarbon dates ranging from 11,960 to 12,970 cal. BP. These dates cluster in two groups (Figure 2). Group 1 is composed of five dates ranging from circa 12,000 to 12,400 cal. BP, producing a mean age of 12,270 cal. BP. Group 2 is composed of four dates ranging from circa 12,750 to 13,000 cal. BP, with a mean age of 12,890 years. All projectile points from these deposits are Western Stemmed Tradition Haskett points.


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