The allure of the bottom of the Grand Canyon finally proved to be too great to ignore and early in November we headed off down the South Kaibab Trail for Bright Angel Campground and several days of backpacking. While this one really doesn't quite count as fieldwork, it was definitely worth the effort and gave us plenty to think about!

Above: Left - The view down the South Kaibab Trail. Still a long knee-beater downhill walk to go to get to the bottom. Right - A small Anasazi masonry pueblo located near the outlet of Bright Angel Creek. The pueblo consists of four rooms (living areas, storage room, and kiva) and was occupied between A.D. 1060 and A.D. 1150. The inhabitants grew corn, beans, and squash alongside the creek.

Below: The entrance to Bright Angel Canyon as seen from the south side of the Colorado River. The campground is located in the grove of trees at the canyon mouth.

Summer ends early in the Oregon High Cascades and so we were soon back out again in mid-September for a visit to Rock Mesa and a little-known geographic feature that's had our interest for many years: Indian Holes. For a 360-degree view of the Rock Mesa obsidian flow and the surrounding Wickiup Plains pumice flat, click HERE.

Above: Left - Rock Mesa. The Wickiup Plain is the the foreground, the South Sister is in the background, and the 2,000 year-old Rock Mesa obsidian flow lies in between. Right - The pile of rubble on the left marks the edge of the Rock Mesa obsidian flow. The pumice flat on the right (west side of the flow) consists of tephra and angular chunks of porphyritic obsidian that were explosively ejected from the Rock Mesa vent prior to the extrusion of the flow.

Below: Left - Indian Holes Falls, a pleasant scenic surprise at the end of the long trail down to Indian Holes. For the last 20 years, We've been meaning to get down here to see if there was some archaeological significance to the name. Right - Indian Holes. We couldn't find any holes and there's no visible evidence of prehistoric activity here but there is a large open meadow bounded by springs and criss-crossed by a labyrinth of incised rivulets - the holes?

At the beginning of September, we again set off into the Three Sisters Wilderness with Obsidian Cliffs as our destination and finally made it this time. The obsidian and rhyolite flow that makes up the Obsidian Cliffs source extends about a mile and a half from the vent area near Sisters Spring to the 300 ft-high cliffs that mark the end of the flow. Much of the upper and lower plateau areas atop the flow are covered by obsidian debitage and nodules of raw material. For a 360-degree view of the upper plateau of the flow, click HERE.

Above: Left - THE Obsidian Cliffs, the terminus of the obsidian-rhyolite flow. Right - Heading across the top of the Obsidian Cliffs flow on the lower portion of the plateau. The ground by the hiker is littered with obsidian flakes.

Below: Left - A view of the upper portion of the Obsidian Cliffs flow plateau. Right - Flakes and nodules of obsidian cover much of the upper plateau.

In mid-August, we headed into the Three Sisters Wilderness from McKenzie Pass towards Obsidian Cliffs. Throughout the years at the lab, we've run across approximately 4,500 chemically-characterized artifacts from this source, making it (along with Newberry Volcano) one of the most commonly-encountered (and intensively-utilized) archaeological obsidian sources in the State of Oregon. Thanks to the arrival of unseasonably-inclement weather on day 3, we had to head back only a few miles short of our destination. Next time, hopefully a little later this season, we'll once again make the attempt from a lower-elevation trailhead. For a 360-degree view of the area from the summit of Collier Cone (just as the weather was rolling in), click HERE.

Above Left: The view to the west from near the summit of Collier Cone. Obsidian Cliffs is the protruding flow in the center of the picture.

Above Right: A view of the spectacular Obsidian Cliffs flow from the top of Collier Cone. So near, yet so far.

For the last 25 years, we've been scouring the gravel bars and alluvial deposits of northwestern Oregon for small waterworn nodules of obsidian and, in recent years, have been joined in the search by Dick Pugh of the Cascadia Meteorite Laboratory. Trace element studies of the recovered obsidian nodules indicate that five different geochemical sources are represented in the gravels of the Willamette Valley: Inman Creek A, Inman Creek B, Obsidian Cliffs, New Era, and the elusive Carver Flow/Unknown B. Of these four sources, the two Inman Creek varieties are clearly the most abundant in the Willamette Valley and were the most intensively utilized by the prehistoric residents of the region. Archaeological investigations of sites in the Willamette Valley almost invariably turn up significant quantities of small split obsidian nodules, debitage with traces of waterworn cortex, and small formed tools that have been manufactured from these locally-obtained nodules of glass.

Above Left: Some of the best sources of these obsidian nodules lie north of Eugene along Willamette River gravel bars that are often accessible primarily by boat. Our two-day late July kayak reconnaissance of the river between Harrisburg and Corvallis turned up numerous potential sampling locations along the way along with a small quantity of obsidian for analysis. More field work will clearly be required.

Above Right: These two glass nodules were collected from an isolated gravel bar several miles upriver from Corvallis. In the image above, we've sawn the two pebbles in half with a lapidary saw to prepare an optimal X-ray target surface - the smaller nodule is from the Inman Creek A source and the larger sample is from the Obsidian Cliffs flow situated in the Three Sisters area of the High Cascades.

Two weeks later found us once again cruising the gravel bars of the Willamette River, this time on isolated trails running south from Corvallis along the Willamette River. Instead of a kayak, we used our trailworthy Bike Friday Pocket Llama mountain bike/mobile human-powered field vehicle and managed to find a couple of more hard-to-spot obsidian nodules in the gravel beaches along the river. Subsequent XRF analysis of the nodules proved them to be from the local Inman Creek A source.

And two weeks later we were back out on the river between Peoria and Corvallis and collected three more obsidian nodules - two from Obsidian Cliffs and one from the Carver Flow/Unknown B source.

We'll be back on the river in 2010 - to follow our progress on Google Maps, click HERE.

July took us to the Reno Basin and the Truckee River Canyon east of Sparks, Nevada. The small obsidian nodules above (2.4 cm-diameter quarter for scale), marakenites associated with the CB Concrete quarry located on the east side of Truckee Meadows in Reno, are the result of a 45-minute search in front of the quarry. We also stopped by Lagomarsino Canyon along the Truckee River Canyon to explore access to the fine-grained volcanic materials that are found in that area. Also rumored to be located nearby in the Patrick area along the Truckee River is the Patrick obsidian source. If it's there somewhere, however, we couldn't find it after a thorough search along the river terraces.

May field work took us southeast through Nevada and towards the North Rim of the Grand Canyon. The view above shows the western slopes of the Santa Rosa Range in north central Nevada. High-quality obsidian (Paradise Valley geochemical source) is found in surficial and secondary deposits throughout the valley and south towards the town of Paradise Valley. The 9,732 ft-high Granite Peak is in the background.

While driving down the central Nevada's Monitor Valley on our way to try and locate the Box Spring source, we ran across a prominent 150 foot-tall hill of sinter with a surprise on top - Diana's Punchbowl. Click HERE for a video view. Image taken looking north up the valley.

Above: Late in the day at the remote Toroweap Camground - the 60 mile-long gravel road that leads here and lack of amenities like water tends to weed out the casual visitors. The Colorado River is located a five minute walk south and a half mile down from the campground.

Below: The lab director contemplates the notion of the Grand Canyon as a potential prehistoric barrier - 2700 feet below is the Colorado River. Despite the notion that the canyon might have posed an impediment to regional movement, trace element studies of obsidian artifacts from along the North Rim indicate that sources across the canyon from the San Francisco and Mount Floyd volcanic fields near Flagstaff are commonly represented.

Looking west from a few miles north of the Nevada-Oregon border into the Guano Valley, southcentral Oregon. Secondary deposits of obsidian from the Massacre Lake/Guano Valley source are common on the valley floor and we've been gradually trying to refine the geographic boundaries of this source over the years. On this visit, we collected obsidian from the far side of the valley in an attempt to find a new and geochemically-distinctive obsidian source that previously showed up along with the expected Massacre Lake/Guano Valley samples. Subsequent XRF analysis of the samples collected on this trip didn't reveal the new source but we did stumble across the most northernmost occurrence of secondary Badger Creek glass that we've yet found.

Above: Panoramic April view of the Glass Buttes Obsidian Source Complex from the southern margin of Misery Flat - Glass Butte is on the right and Little Glass Butte is the peak near the center. We believe that we've found all of the different Glass Buttes obsidian varieties (nine of them) and we're now focusing on the identification of the geographic boundaries of the different geochemical sources.

Below: Left - A fault-controlled natural perennial water tank and drainage leading away from the Glass Buttes primary source areas. This is one of several natural tanks in this region. Trace element analysis of 30 obsidian nodules from this location indicates that five of the nine geochemical Glass Buttes chemical varieties of glass are found in the drainage that runs through the tank. Glass Butte is visible to the south in the background. Right - The ground near the water source is littered with obsidian flakes and this was clearly a prehistoric place of interest.

Above: Left - The peak behind Wizard Island is Llao Rock, a minor and somewhat marginal source of obsidian in Crater Lake National Park. To our knowledge, no prehistoric artifact has ever been traced to this source. This obsidian-rhyolite flow filled an explosion crater left behind by the 7,015 B.P. eruption that preceded the climactic eruption of Mount Mazama. The slightly later explosive eruptions and caldera collapse that created the basin filled by Crater Lake exposed a spectacular profile of the flow in the present-day caldera wall. Right: Another view of Llao Rock from the Cloudcap viewpoint.

Below: Left - Obsidian is best-exposed along a roadcut on the western portion of the flow. Right - This is about as good as the quality of the glass at this location gets.

View of the lab director from near the summit of Paulina Peak. We were in the area and it was an unusually clear day and so we headed to the top of Paulina Peak for some photos of the obsidian flows in the caldera. The Big Obsidian Flow is in the background.

In the picture above, we're standing atop Vulcan's Thone, an 800 ft-high Pleistocene cinder cone on the North Rim of the Grand Canyon in northern Arizona. Click on the picture above or HERE for more details - you'll need Java enabled to look at some of the images. Ever since we began running into obsidian artifacts to the north of the canyon that originated from obsidian sources on the south side of the Grand Canyon, we've been thinking hard about the influence of geographic barriers to the movement of artifacts and wanted to see for ourselves just what kind of a barrier the canyon might be. A formidable one, to be sure, but apparently still porous. Toroweap Point can be seen near the lefthand edge of the image.

Above: Bodie Hills, California - a view west down Aurora Canyon and a close look at the glass nodules and flakes that litter the ground in this area. On the way south to the North Rim, we visited several archaeologically-significant obsidian sources along the east side of the Sierra Nevada Range - Sutro Springs, Bodie Hills, and Mono Craters. Obsidian from these Bridgeport area sources is widely distributed at sites along the eastern margin of the Sierras and is also found in surprisingly large quantities at sites in central California and along the central California Coast, the result of a very active trans-Sierran obsidian procurement and exchange system.

Below: Mono Craters, California - Mono Lake is in the foreground. The late Holocene (13th century A.D.) volcanic activity that produced Mono Craters created a 10 mile-long chain of obsidian domes and flows (including two islands in Mono Lake). Unlike the more widely-distributed obsidian from other nearby sources - Casa Diablo, Bodie Hills, Mono Glass Mountain, and Mt. Hicks (NV) - artifacts manufactured from Mono Craters obsidian are largely restricted to the immediate region around the local Mono Basin.

Above: We're back from a fast foray to the South Sister Volcano and Broken Top area of Oregon's central High Cascades where we were looking at the distribution of obsidian from Tumalo Creek. This is an obscure and poorly-known source of glass located on the eastern slopes of Broken Top and one that only rarely shows up in the archaeological record. In the photo above taken looking north from Sparks Lake, South Sister Volcano is in the background - a 2,000 yr-old chain of poor-quality obsidian domes stretches south towards the lake. The pictograph that serves as the lab logo was copied from rock art found on the southernmost of these domes.

Below: A view of Obsidian Cliffs, one of Oregon's most archaeologically-significant sources of obsidian, looking southeast from across Lost Creek Canyon. We had intended to spent a couple of days at the source but plans were derailed by an unexpected road closure in 2007. Instead we ended up looking for nodules of obsidian in glacial moraines - the source was overriden by glaciers in the late Pleistocene and chunks of glass were transported westward into the McKenzie River drainage (and from there eventually into the Willamette Valley). The prominent cliffs near the center of the image below mark the western terminus of the obsidian-rhyolite flow. The Little Brother and North Sister loom in the background.

Above: The view of Newberry Caldera from the summit of Paulina Peak - it was an unusually clear day just prior to the outbreak of several large fires in eastern Oregon. The 1,350 year-old Big Obsidian Flow is located on the righthand side of the panorama. Also within the field of view are several other archaeologically-significant post-Mazama flows of obsidian, most of which share the same trace element signature, the Newberry Volcano source group. Although we've had samples from the caldera obsidian flows in the lab source reference database for many years, we recently managed to relocate a Newberry Volcano source flow that lies outside the boundaries of the caldera on the southeast flanks of the volcano. The unit is thickly mantled by tephra deposits and was found by chance in the mid-1980's during a visit to the very obscure Little Obsidian Flow. That small post-Mazama flow is covered by tephra from the eruptions at the Big Obsidian Flow vent but does not appear to be a source of any artifact-quality glass.

While we were in the area in 2006, we had another quick and unproductive look for the elusive Unknown X obsidian source that we suspect is located somewhere within a few miles of the McKay Butte source. The Unknown X obsidian, a popular pre-Mazama toolstone source, was first identified in 1991 from provenance studies carried out during the extensive PGT-PG&E Pipeline Expansion Project that ran immediately west of Newberry Volcano. Guided by geologic mapping of Newberry Volcano, we have a checklist of possible source localities to look over in the near future.

Below: Vent Cave, one of several small severely-disturbed (by pothunters) lava tubes located on the northern side of Newberry Volcano in the Lava Top Butte vicinity. We've been meaning to wrap up some long postponed obsidian provenance research at these caves (two of which are perennial water sources) and will soon have a last look at the caves (if we can find them all again).

Above:Once again, we're back at Glass Buttes ... here's the view looking north from the eastern end of the Glass Buttes source complex (June 2006). The massive outcrops of obsidian at Glass Buttes have been a lab research priority for the last several years and we continue to add more sampling locations whenever we're in the area. So far, we've identified nine geochemically-unique sources of obsidian at the complex and in secondary deposits in the basins to the north and south of the main source area. At this point, it seems likely that we won't find any new sources but there's still a lot to learn about the boundaries of availability for the different sources.

Below: Looking north from Wagontire Mountain across the Sinks of Lost Creek basin towards the south side of the Glass Buttes Source Complex. Secondary deposits of glass from several of the Glass Buttes geochemical varieties are common in the basin to the south of the source complex.

Above: Left - Here's the classic view of Fort Rock, a spectacular Pleistocene tuff ring located in the Fort Rock Basin of Oregon. The landform once stood as an island in the late Pleistocene Pluvial Fort Rock Lake but was high and dry by the time the area was inhabited. Right - The well-known Fort Rock Cave is visible in the middle distance from the top of Fort Rock.

Below: Looking north towards Cougar Mountain, the most significant source of natural glass to the prehistoric inhabitants of the area. In 2006, we began a systematic survey of area gravel pits and other lacustrine deposits in order to better understand the widespread natural distribution of obsidian nodules that originated from Cougar Mountain.

Above: A perennial tank of water located in a fault-controlled intermittent stream drainage in the Wagontire vicinity. Obsidian from two different sources, Tank Creek and Big Stick, was identified among the glass nodules collected from fluvial deposits at this location. Another nearby natural tank awaits a visit. Wagontire Mountain lies in the distance.

The region from the Wagontire Mountain area east to the Harney-Malheur Basin has proven to be a vertitable treasure trove of poorly-known and prehistorically-significant obsidian sources. These range from geographically constrained sources (e.g., Bald Butte and China Lake) to those that have been naturally distributed downlope through complex drainage systems (e.g., Wagontire Mountain, Tank Creek, and Big Stick) to those that are associated with massive eruptions of volcanic ashflow tuffs that cover large geographic areas (e.g., Buck Springs). We think that we've now located most of the extant unique geochemical obsidian sources in the region and are focusing on understanding their natural geographic distribution.

Below: Hidden away on the isolated northern slopes of Wagontire Mountain are a series of springs and the perennial (but short) Lost Creek. Although the area has been thoroughly disturbed by generations of cattle grazing, evidence of the prehistoric use of the springs is abundant in the form of obsidian flakes from Glass Buttes and other sources to the east. The summit of Glass Buttes can be seen in the far distance peeking above the end of the valley.

Above and Below: We're still not done scouting out the Dry Creek drainage for nodules of obsidian from several geographically widespread sources bordering the stream. The glass has been transported down this drainage as far east as the Owyhee River. We have yet to get to the remote Dry Creek Gorge in the central portion of the drainage but plan to soon.

A view east from the Quinn River towards the Santa Rosa Mountains of northern Nevada. The archaeological site at this spot is located only a few miles southeast from the Double H Mountains obsidian source and small nodules of culturally-unmodified glass from the Double H source are common in the river terrace deposits. Working in conjunction with Craig Young and Steve Neidig (Far Western Anthropological Research Group), we've recently finished a study of the geochemistry of the Double H obsidian source and a sampling of archaeological sites near the source. Initial indications are that the source is geochemically quite variable and covers a much larger than anticipated geographic area.