{{Short description|Paleontological site in Colorado, United States}} {{Coord|39.21|N|106.93|W|region:US-CO_typelandmark|display=title}} [[File:Snowmastodon Project poster.jpg|thumb|right|Poster for the Snowmastodon Project of the [[Denver Museum of Nature & Science]].]]
The '''Snowmastodon site''', also known as the '''Ziegler Reservoir fossil site''', is the location of an important [[Last Glacial Period|Ice Age]] [[fossil]] excavation near [[Snowmass Village, Colorado]]. Fossils were first discovered on October 14, 2010, during the construction of a {{Convert|5|ha|acre}} reservoir to supply Snowmass Village with water.<ref name="Johnson2012">{{cite book|last1=Johnson|first1=Kirk|last2=Miller|first2=Ian|title=Digging Snowmastodon: Discovering an Ice Age World in the Colorado Rockies|date=March 22, 2012|publisher=People's Press|isbn=978-1936905065|pages=144|edition=1st}}</ref> Over the subsequent weeks, after an agreement had been reached to allow paleontological excavation, crews from the [[Denver Museum of Nature & Science]] and the [[U.S. Geological Survey]] worked along with the construction crews as more fossil material was uncovered.<ref name=Johnson2012 /> The site closed for five months over the winter, reopening May 15, 2011. Between May 15 and July 4, 2011, crews from the Denver Museum of Nature & Science conducted a large scale fossil excavation alongside construction crews building a dam for the reservoir. In total over 36,000 [[vertebrate]] fossils (including [[mammoths]], [[mastodons]], [[ground sloths]], [[Equidae|horses]], [[Camelini|camels]] and [[deer]]), more than 100 species of fossil [[invertebrate]]s and over 100 species of fossil plants were found in sediments deposited by an alpine lake during the last [[interglacial period]].<ref name="Johnson2014">{{Cite journal |last1=Johnson |first1=Kirk R. |last2=Miller |first2=Ian M. |last3=Pigati |first3=Jeffery S. |last4=Snowmastodon Project Science Team |date=November 2014 |title=The Snowmastodon Project |journal=[[Quaternary Research]] |volume=82 |issue=3 |doi=10.1016/j.yqres.2013.12.010}}</ref>
== Discovery == [[File:Mammuthus columbi Sergiodlarosa.jpg|thumb|right|[[paleoart|Artist's restoration]] of a [[Columbian mammoth]] (''Mammuthus columbi''), the first [[fossil]] [[species]] recovered from the site.]] [[File:Mammut americanum Sergiodlarosa.jpg|thumb|right|[[paleoart|Artist's restoration]] of an [[American mastodon]] (''Mammut americanum''), the most numerous of the [[megafauna]] discovered in the Snowmass Village fossil site.]] [[File:Camelops hesternus Sergiodlarosa.jpg|thumb|right|[[paleoart|Artist's restoration]] of ''[[Camelops]]'']]
The fossil site was discovered on October 14, 2010, by Gould Construction Inc. crews who had been employed by the Snowmass Water and Sanitation District (SWSD) to expand the [[Ziegler Reservoir]] and provide additional water supplies to the nearby town of [[Snowmass Village, Colorado|Snowmass Village]].<ref name="gould">
{{cite web |url = http://engineering.colorado.edu/news/cue/2011/alumni/gould.htm |title = Significant Fossil Find Unearthed in Colorado by Gould Construction |publisher = CU Engineering, University of Colorado |access-date = July 8, 2011 |url-status = dead |archive-url = https://web.archive.org/web/20120120020213/http://engineering.colorado.edu/news/cue/2011/alumni/gould.htm |archive-date = January 20, 2012 }}
</ref><ref name=aspent>
{{cite news | author = Janet Urquhart | title = 'One-stop shopping for the Ice Age' near Snowmass | url = http://www.aspentimes.com/article/20110526/NEWS/110529882 | access-date = 5 July 2011 | newspaper = Aspen Times | date = 26 May 2011}}
</ref><ref name="faq"> {{cite book|title=This citation no longer exists}}</ref>
While clearing the perimeter of the reservoir, [[bulldozer]] operator Jesse Steele unearthed the first animal bones.<ref name="spin">
{{cite web | url = http://www.aspenspin.com/journal/2010/11/14/snowmass-ground-score.html | title = Snowmass Ground Score | date = November 14, 2010 | publisher = AspenSpin.com | access-date = July 8, 2011}}</ref>
Recognizing them as possible fossils, Steele informed project foreman, Kent Olson. Olsen took the bones home and identified them as belonging to a mammoth using sources he found on the internet. The next morning, Kit Hamby, the district manager for the Snowmass Water and Sanitation District (SWSD), contacted a contractor from the Colorado Geological Survey who contacted the Denver Museum of Nature & Science (DMNS).<ref name=Johnson2014 /> The DMNS reached an agreement with the SWSD to allow the museum to excavate the fossils.
Crews from the Denver Museum, U.S. Geological Survey, and several other institutions work alongside bulldozers for two weeks in order to salvage the increasing number of fossils being unearthed.<ref name=Johnson2014 /> The onset of winter caused the site to be closed for five months beginning November 15.<ref name=Johnson2014 /><ref name=Johnson2012 /> When the excavation resumed on May 15, 2011, museum crews had 7 weeks to complete the excavation in order for the reservoir project to be completed on time.<ref name=Johnson2014 />
By the time excavation had been completed, the team consisting of more than 250 volunteers and 40 project scientists removed approximately 8000 cubic meters of sediment.<ref name=Johnson2014 /><ref name=Johnson2012 /> Thousands of fossils were collected along with stratigraphic, geochronologic, palynologic, paleoentomologic, and paleobotanic data that was subsequently used to reconstruct the paleoecosystem at ancient Lake Ziegler.<ref name=Johnson2014 />
==Snowmastodon Project== A $10.5 million dam for the reservoir was scheduled to be completed by mid-October 2011, with the site was expected to be underwater by November 2011.<ref name="css"/> For that reason, any paleontological excavation had to be done quickly.<ref name="amazingrate">{{cite news|url=http://www.aspentimes.com/article/20110616/NEWS/110619879|title=Snowmass fossil dig yields bones at 'amazing rate'|author=Janet Urquhart|date=June 16, 2011|newspaper=The Aspen Times|access-date=July 8, 2011}}</ref> The excavations were led by the Denver Museum of Nature & Science, together with the U.S. Geological Survey and scientists from at least 19 institutions.<ref name="css">{{cite journal|author=Jeff Pigati & Kirk Johnson|year=2011|title=The Snowmastodon Site: Discovery, Science, and Initial Results|journal=Newsletter of the Society|pages=2|publisher=Colorado Scientific Society|url=http://www.coloscisoc.org/news/2011/Feb_2011cssNews.pdf|access-date=July 11, 2011 }}</ref><ref name="usgs">{{cite web | url = https://www.usgs.gov/newsroom/article.asp?ID=2643|title=Snowmass Fossil Site Provides Opportunity to Study Past Vegetation and Climate in Colorado|author=Marissa Lubeck|date=November 18, 2010|publisher=USGS Newsroom, U.S. Geological Survey|access-date=July 11, 2011}}</ref> The Snowmastodon Project, as the efforts had been dubbed, cost approximately $1 million, including public outreach programs.<ref name="stroud">{{cite news|url=http://enews.coloradomtn.edu/2011/07/06/area-teachers-diggin-what-they-learned-at-snowmass-fossil-site/|title=Area teachers diggin' what they learned at Snowmass fossil site|author=John Stroud|date=July 2, 2011|newspaper=Glenwood Springs Post Independent|access-date=July 8, 2011}}</ref> Half of the costs were covered by grants and gifts to the museum, while the rest came from donations.<ref name="navratil">{{cite news|url=http://www.denverpost.com/news/ci_18395768|title=Colorado fossil diggers at Snowmass site pack up bones so dam can be built|author=Liz Navratil|date=July 2, 2011|newspaper=Denver Post|access-date=July 8, 2011}}</ref>
The first scientific excavation officially began on November 2, 2010. It involved 67 workers from the Denver Museum of Nature & Science, and lasted 12 days. Preliminary efforts concluded on November 14, 2010, when the arrival of winter prevented any further excavation.<ref name="timeline"> {{Cite web |title=Discovery Timeline |url=http://www.dmns.org/science/the-snowmastodon-project/project-updates |archive-url=https://web.archive.org/web/20140828143814/http://www.dmns.org/science/the-snowmastodon-project/project-updates/ |archive-date=28 August 2014 |publisher=Denver Museum of Nature & Science |access-date=12 August 2023}}</ref> The site and fossils left ''in situ'' were protected with frost-free barrier and the recovered fossils taken to the conservation laboratory of the DMNS. More than 600 bones and 130 plant, rock, and invertebrate samples were recovered, including the first mastodon skull ever recovered in Colorado (unearthed a mere day after the beginning of the excavation) and the first remains of a Jefferson's ground sloth to be found in the state. Other [[megafauna]] recovered included [[giant bison]], two [[deer]]-like animals, and more mammoths.<ref name=dpost2010>{{cite news|url=http://www.denverpost.com/news/ci_16653883#ixzz1RGomKED8|title=Denver museum staff euphoric over ice-age fossil finds|author=Electra Draper|date=November 19, 2010|newspaper=Denver Post|access-date=July 8, 2011}}</ref>
Excavations resumed during spring of 2011, from May 15 to July 4, with the support and permission of SWSD and the State of Colorado.<ref name="MuseumAgreements">{{cite web|last1=Urquhart|first1=Janet|title=Museum reaches agreements to resume Snowmass fossil dig|url=http://www.aspentimes.com/news/museum-reaches-agreements-to-resume-snowmass-fossil-dig/|website=Aspen Times|access-date=11 May 2011}}</ref> By the end of July, the total number of bones recovered was around 36,000, from at least 52 different Ice Age vertebrate animals.<ref name="conclude">{{Cite web |last=Johnson |first=Kirk |date=7 July 2011 |title=Museum Concludes Ice Age Fossil Excavation |url=http://www.dmns.org/science/the-snowmastodon-project/project-updates/snowmass-posts/museum-concludes-ice-age-fossil-excavation |archive-url=https://web.archive.org/web/20110711123543/http://www.dmns.org/science/the-snowmastodon-project/project-updates/snowmass-posts/museum-concludes-ice-age-fossil-excavation |archive-date=11 July 2011 |publisher=Denver Museum of Nature & Science |access-date=12 August 2023}}</ref> Approximately 3,000 of them are believed to come from [[mastodon]]s of both sexes and of varying ages, from infants to full adults.<ref name="WorkWrapsUp" >{{cite news|url=http://www.postindependent.com/article/20110701/VALLEYNEWS/110639990|title=Work wraps up at one of 'world's great fossil sites'|author=Janet Urquhart|date=July 1, 2011|newspaper=Glenwood Springs Post Independent|access-date=July 8, 2011}}</ref> Other new animals recovered included an Ice Age camel, a horse, and various smaller vertebrates.<ref name="conclude"/><ref name=nyt070411>{{cite news|author=Kirk Johnson|title=Pleistocene Treasures, at a Breakneck Pace|url=https://www.nytimes.com/2011/07/05/science/05dig.html|access-date=5 July 2011|newspaper=New York Times|date=5 July 2011}}</ref>
A small excavation crew from the museum remained at the site, in the event further discoveries were made in the course of the dam construction.<ref name="AspenTimes2011">{{cite news|url=http://www.snowmasssun.com/article/20110511/FRONTPAGE/110519997|title=Fossil frenzy returns to Ziegler Reservoir|author=Madeleine Osberger|date=May 11, 2011|newspaper=Snowmass Sun|access-date=July 8, 2011}}</ref>
The speed at which the fossils were recovered (more or less seven weeks) is remarkable for a scientific dig of this size. Kirk R. Johnson, leader of the Snowmastodon Project on behalf of the Denver Museum of Nature & Science, told the New York Times, ''"The speed of this thing is so unlike normal science — from discovery to completion of one of the biggest digs ever in less than nine months."''<ref name=nyt070411/>
Scientists are not concerned now that the site is covered by water after completion of the reservoir expansion. Being underwater helps preserve the fossils and the reservoir can be drained if ever the need arises for additional excavations.<ref name="cbs">{{cite news|url=http://denver.cbslocal.com/2011/07/08/museum-to-show-off-thousands-of-bones-unearthed-near-snowmass/|title=Museum To Show Off Thousands Of Bones Unearthed Near Snowmass|date=July 8, 2011|publisher=CBS Denver|access-date=July 11, 2011}}</ref>
==Importance== The Ziegler Reservoir fossil site is one of the few localities in North America from the [[Sangamonian|Sangamonian Stage]], and the only one at high elevation.<ref name=Johnson2014 /> This site preserves multiple alpine ecosystems stacked on top of each other within sediments of ancient alpine lake. Among the [[vertebrate]] fauna, this site represents highest known elevations of a number of species.<ref name=Sertich2014 /> Additionally, this site holds the record for the most mastodons preserved in a single location, including the largest mastodon ever found.<ref name=Johnson2012 /><ref name="Fisher 2014">{{cite journal|last1=Fisher|first1=Daniel C.|last2=Cherney|first2=Michael D.|last3=Newton|first3=Cody|last4=Rountrey|first4=Adam N.|last5=Calamari|first5=Zachary T.|last6=Stucky|first6=Richard K.|last7=Lucking|first7=Carol|last8=Petrie|first8=Lesley|title=Taxonomic overview and tusk growth analyses of Ziegler Reservoir proboscideans|journal=Quaternary Research|date=November 2014|volume=82|issue=3|pages=518–532|doi=10.1016/j.yqres.2014.07.010}}</ref> The fossil flora offer unprecedented insights into plant biogeography of the [[Rocky Mountains]] during the last interglacial period.<ref name="DMiller 2014">{{cite journal|last1=Miller|first1=Dane M.|last2=Miller|first2=Ian M.|last3=Jackson|first3=Stephen T.|title=Biogeography of Pleistocene conifer species from the Ziegler Reservoir fossil site, Snowmass Village, Colorado|journal=Quaternary Research|date=November 2014|volume=82|issue=3|pages=567–574|doi=10.1016/j.yqres.2014.06.003}}</ref>
The site is also important for the exceptional preservation of fossil material. Fossil sedge and willow leaves were still green, conifer cones were still intact, and large driftwood logs were preserved.<ref name=Johnson2014 /> In addition, the mollusks and gastropods showed color, and beetle parts were still iridescent.<ref name=Johnson2014 /> Vertebrate fossil material was in excellent condition as well.<ref name=Johnson2014 />
The [[National Geographic Society]], which donated a $55,000 grant to the project, featured the site in the ''[[National Geographic Magazine]]'' . The science television series ''[[Nova (American TV series)|Nova]]'' broadcast an episode <ref name="nova">{{cite web|url=https://www.pbs.org/wgbh/nova/insidenova/2012/02/discovering-snowmastodon.html|title=PBS Television Series Nova: Discovering Snowmastodon}}</ref> about the site in February, 2012.
==Geologic setting and geochronology== The Ziegler Reservoir occupies an unusual geologic setting on top of a ridge {{Convert|2705|m|ft|order=flip}} above sea level. The lake basin was formed when a glacier flowing down Snowmass Creek Valley became thick enough to overtop the adjacent ridgeline.<ref name=Pigati2014>{{cite journal|last1=Pigati|first1=Jeffery S.|last2=Miller|first2=Ian M.|last3=Johnson|first3=Kirk R.|last4=Honke|first4=Jeffery S.|last5=Carrara|first5=Paul E.|last6=Muhs|first6=Daniel R.|last7=Skipp|first7=Gary|last8=Bryant|first8=Bruce|title=Geologic setting and stratigraphy of the Ziegler Reservoir fossil site, Snowmass Village, Colorado|journal=Quaternary Research|date=November 2014|volume=82|issue=3|pages=477–489|doi=10.1016/j.yqres.2013.12.011|url=https://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1946&context=usgsstaffpub|url-access=subscription}}</ref> As the glacier retreated, a moraine impounded a 5 hectare alpine lake that was initially 10 meters deep.<ref name=Pigati2014 /> Over time, the lake filled in with wind-blown sediments until it became a marshland and ultimately an alpine meadow.<ref name=Pigati2014 /> After Doug Ziegler and his family purchased the land that now contains the Ziegler Reservoir, they commissioned the construction of a small earthen dam in 1961 to block the meadow drainage and form a shallow, private lake that persisted until the Snowmass Water and Sanitation District bought the water rights in 2010.<ref name=Pigati2014 /> Several dating techniques were employed in order to determine the age of the ancient lake sediments. Attempts at [[radiocarbon]] dating of lake organics, bone collagen and shell carbonate, revealed that the site was radiocarbon dead or greater than 45,000 years old.<ref name=Mahan2014>{{cite journal|last1=Mahan|first1=Shannon A.|last2=Gray|first2=Harrison J.|last3=Pigati|first3=Jeffery S.|last4=Wilson|first4=Jim|last5=Lifton|first5=Nathaniel A.|last6=Paces|first6=James B.|last7=Blaauw|first7=Maarten|title=A geochronologic framework for the Ziegler Reservoir fossil site, Snowmass Village, Colorado|journal=Quaternary Research|date=November 2014|volume=82|issue=3|pages=490–503|doi=10.1016/j.yqres.2014.03.004}}</ref> [[Surface exposure dating|''In situ'' cosmogenic]] [[beryllium]] and [[aluminum]] from a boulder that was part of the bounding moraine yielded an age of approximately 140,000 years old.<ref name=Mahan2014 /> [[Uranium-series dating]] of vertebrate fossils confirmed the age range of 45,000-140,000 years; however, the extremely low uranium concentrations limited the utility of that method.<ref name=Mahan2014 /> [[Optically stimulated luminescence]] (OSL) ages obtained from the fine-grained quartz provided reliable, replicable ages for the sediments within the established 45,000 – 140,000 time frame.<ref name=Mahan2014 /> The dates obtained via OSL correlate with the end of the [[Bull Lake glaciation]] and the [[Sangamonian|Sangamon interglacial stage]], spanning [[marine isotope stage]]s 6 through 4.<ref name=IMiller2014>{{cite journal|last1=Miller|first1=Ian M.|last2=Pigati|first2=Jeffery S.|last3=Anderson|first3=R. Scott|last4=Johnson|first4=Kirk R.|last5=Mahan|first5=Shannon A.|last6=Ager|first6=Thomas A.|last7=Baker|first7=Richard G.|last8=Blaauw|first8=Maarten|last9=Bright|first9=Jordon|last10=Brown|first10=Peter M.|last11=Bryant|first11=Bruce|last12=Calamari|first12=Zachary T.|last13=Carrara|first13=Paul E.|last14=Cherney|first14=Michael D.|last15=Demboski|first15=John R.|last16=Elias|first16=Scott A.|last17=Fisher|first17=Daniel C.|last18=Gray|first18=Harrison J.|last19=Haskett|first19=Danielle R.|last20=Honke|first20=Jeffery S.|last21=Jackson|first21=Stephen T.|last22=Jimenez-Moreno|first22=Gonzalo|last23=Kline|first23=Douglas|last24=Muhs|first24=Daniel R.|last25=Nash|first25=Stephen E.|last26=Newton|first26=Cody|last27=Paces|first27=James B.|last28=Petrie|first28=Lesley|last29=Plummer|first29=Mitchell A.|last30=Pornichu|first30=David F.|last31=Rountrey|first31=Adam N.|last32=Scott|first32=Eric|last33=Sertich|first33=Joseph J. W.|last34=Sharpe|first34=Saxon E.|last35=Skipp|first35=Gary L.|last36=Strickland|first36=Laura E.|last37=Stucky|first37=Richard K.|last38=Thompson|first38=Robert S.|last39=Wilson|first39=Jim|title=A high-elevation, multi-proxy biotic and environmental record of MIS 6-4 from the Ziegler Reservoir fossil site, Snowmass Village, Colorado, USA|journal=Quaternary Research|date=November 2014|volume=82|issue=3|doi=10.1016/j.yqres.2014.01.014}}</ref>
==Vertebrate fauna== Over 36,000 bones and teeth belonging to 52 [[taxa]] of macro- and microvertebrates were uncovered during the construction of Ziegler Reservoir.<ref name=Sertich2014 /> These taxa represent a diverse assemblage of fauna belonging to the [[Rancholabrean]] [[North American Land Mammal Age]].<ref name=Sertich2014 /> The smaller vertebrate species include: [[trout]], [[frog]], [[salamander]], [[snake]], [[lizard]], [[duck]], [[goose]], [[pheasant]], [[crane (bird)|crane]], [[finch]], [[shrew]], [[North American river otter|river otter]], [[bear]], [[coyote]], [[rabbit]], [[chipmunk]], [[squirrel]], [[beaver]], [[mice]] and other small [[rodents]].<ref name="Sertich2014">{{cite journal|last1=Sertich|first1=Joseph J. W.|last2=Stucky|first2=Richard K.|last3=McDonald|first3=H. Gregory|last4=Newton|first4=Cody|last5=Fisher|first5=Daniel C.|last6=Scott|first6=Eric|last7=Demboski|first7=John R.|last8=Lucking|first8=Carol|last9=McHorse|first9=Brianna K.|last10=Davis|first10=Edward B.|title=High-elevation late Pleistocene (MIS 6-5) vertebrate faunas from the Ziegler Reservoir fossil site, Snowmass Village, Colorado|journal=Quaternary Research|date=November 2014|volume=82|issue=3|pages=504–517|doi=10.1016/j.yqres.2014.08.002}}</ref> The most abundant species found throughout the site is the [[tiger salamander]].
Also represented in the Ziegler Reservoir are the remains of seven megafauna taxa. These taxa include:
* [[Columbian mammoth]] (''Mammuthus columbi''): Four individuals, including the first fossil recovered from the site (a juvenile nicknamed 'Snowy') were collected.<ref name=Sertich2014 /> * [[American mastodon]] (''Mammut americanum''): The Ziegler Reservoir is the largest site for mastodons in the world with at least 35 individuals present.<ref name=Sertich2014 /> Approximately 60% of the total number of vertebrate elements recovered belong to the American mastodon. * [[Megalonyx|Jefferson's ground sloth]] (''Megalonyx jeffersonii''): Three individuals, one adult and two juveniles, were found at the site. This marks the first time this species has been found in Colorado.<ref name=Sertich2014 /> * [[Bison latifrons|Giant bison]] (''Bison latifrons''): At least 10 individuals were found making the Ziegler Reservoir one of only three sites to produce multiple individuals of ''B. latifrons'' and the highest known elevation for this species.<ref name=Sertich2014 /> * [[Deer]]: At least two individuals of indeterminate species.<ref name=Sertich2014 /> * [[Camelops]]: A single tooth belonging to the extinct camel genus ''Camelops'' was found in lake-center deposits. This is the highest known elevation for this genus.<ref name=Sertich2014 /> * [[Horse]]: A single foot bone from an indeterminate species of ''[[Equus (genus)|Equus]]''.<ref name=Sertich2014 />
==Invertebrate fauna== ; Fossil insects A total of 99 taxa of insect were identified from samples spanning the interval of 125,000 to 77,000 years ago.<ref name="Elias2014">{{cite journal|last1=Elias|first1=Scott A.|title=Environmental interpretation of fossil insect assemblages from MIS 5 at Ziegler Reservoir, Snowmass Village, Colorado|journal=Quaternary Research|date=November 2014|volume=82|issue=3|pages=592–603|doi=10.1016/j.yqres.2014.01.005}}</ref> These fossils are the oldest known Pleistocene high elevation insect faunas from the [[Rocky Mountains]].<ref name=Elias2014 /> The fossil assemblages were dominated by [[beetles]], [[ants]], [[midges]], and [[caddisflies]], which were used to document the climatic oscillations during the time represented by the samples.<ref name=Elias2014 />
; Mollusks and ostracodes Sediments containing terrestrial and aquatic [[mollusks]] and [[ostracods]] span 130,000 to 87,000 years ago.<ref name="Sharpe2014">{{cite journal|last1=Sharpe|first1=Saxon E.|last2=Bright|first2=Jordon|title=A high-elevation MIS 5 hydrologic record using mollusks and ostracodes from Snowmass Village, Colorado, USA|journal=Quaternary Research|date=November 2014|volume=82|issue=3|pages=604–617|doi=10.1016/j.yqres.2014.01.014}}</ref> These sediments produced 12 identifiable taxa of terrestrial gastropods, 5 taxa of aquatic bivalves, 8 taxa of aquatic gastropods, along with 7 taxa of ostracodes.<ref name=Sharpe2014 /> These taxa indicate that the ancient lakeshore was a shallow, well-vegetated, fresh water wetland during the time periods sampled.<ref name=Sharpe2014 />
==Fossil flora== A diverse assemblage of plant macrofossils and [[pollen]] was collected during Snowmastodon. Approximately 99 taxa of plant macrofossil, including [[seeds]], [[leaves]], [[Pine needle|needles]], [[Pine cone|cones]], [[twigs]] and [[wood]] were identified.<ref name="Strickland2014">{{cite journal|last1=Strickland|first1=Laura E.|last2=Baker|first2=Richard G.|last3=Thompson|first3=Robert S.|last4=Miller|first4=Dane M.|title=Last interglacial plant macrofossils and climates from Ziegler Reservoir, Snowmass Village, Colorado, USA|journal=Quaternary Research|date=November 2014|volume=82|issue=3|pages=553–566|doi=10.1016/j.yqres.2014.07.008}}</ref> Over 300 specimens of fossil wood were collected ranging in size from small stems to logs greater than 50 cm in diameter and more than 10 m in length.<ref name="Brown2014">{{cite journal|last1=Brown|first1=Peter M.|last2=Nash|first2=Stephen E.|last3=Kline|first3=Douglas|title=Identification and dendrochronology of wood found at the Ziegler Reservoir fossil site, Colorado, USA|journal=Quaternary Research|date=November 2014|volume=82|issue=3|pages=575–579|doi=10.1016/j.yqres.2014.02.006}}</ref> The majority of wood fossils came from the “beach” horizon at the lake margin. Species of [[fir]], [[Douglas fir]], [[spruce]] and [[pine]] were represented.<ref name=Brown2014 /> The pollen collected includes species of [[sagebrush]], spruce, pine, [[oak]], Douglas fir, fir, [[juniper]], as well as [[herbaceous]] and [[aquatic plants]].<ref name="Anderson2014">{{cite journal|last1=Anderson|first1=R. Scott|last2=Jimenez-Moreno|first2=Gonzalo|last3=Ager|first3=Thomas|last4=Porinchu|first4=David F. |title=High-elevation paleoenvironmental change during MIS 6-4 in the central Rockies of Colorado as determined from pollen analysis|journal=Quaternary Research|date=November 2014|volume=82|issue=3|pages=542–552|doi=10.1016/j.yqres.2014.03.005}}</ref>
==See also== {{Portal|Paleontology|North America|<!--Northern America-->|United States|Colorado|Mountains}} * [[Denver Museum of Nature and Science]] * [[List of fossil sites]] * [[Pitkin County, Colorado]] * [[Pleistocene megafauna]] * [[Snowmass Village, Colorado]] * [[Southern Rocky Mountains]]
==References== {{Reflist|30em}}
== External links == * [https://web.archive.org/web/20190903093203/https://www.pbs.org/wgbh/nova/video/ice-age-death-trap/ "Ice Age Death Trap"]—Episode of [[PBS]]'s ''[[Nova (American TV program)|Nova]]'' on the Snowmastodon excavation project, broadcast February 1, 2012 (archive; introduction only)
[[Category:2010 in paleontology]] [[Category:Cenozoic paleontological sites of North America]] [[Category:Geography of Pitkin County, Colorado]] [[Category:Paleontology in Colorado]]