Thermal pool and dark clouds, winter. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49245.html Bisons with snowy faces. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49274.html West Thumb Geyser Basin in winter. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49250.html Lone bison and thermal steam. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49317.html Mirror Pool, snow and steam. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49331.html Old Faithful Geyser in the winter with moon. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49302.html Pine tree and Old Faithful geyser in winter. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49311.html Old Faithful Geyser, daww eruption. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49308.html Bison and Lion Geyser in winter. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49252.html Bare trees and steam in winter. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49264.html Old Faithful geyser, moon and clouds. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49307.html Old Faithful Geyser at dawn. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49309.html Old Faithful geyser plume in winter. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49312.html Snow-covered bison in winter. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49251.html Plume, long night exposure, Old Faithful. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49305.html Plume, Old Faithful geyser, winter night. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49306.html Old Faithful Geyser eruption and moon. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49300.html Old Faithful Geyser erupts at night. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49301.html Night view of Old Faithful Geyser in winter with full moon. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49303.html Run-off and geyser, steam obscuring moon, Old Faithful. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49304.html Sapplings and burned trees in winter. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49284.html Snow-covered trees. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49278.html Snow-covered branches. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49279.html Tree skeletons in winter. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49257.html Wintry forest and steam. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49319.html Steam and forest in winter. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49320.html Thermal steam along the Firehole River in winter. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49281.html Firehole river and bison in winter. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49258.html Buffalo herd and Geyser Hill in winter. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49316.html Snowy landscape with distant thermal pool. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49262.html Winter landscape with thermal run-off. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49255.html Castle geyser cone and steam in winter. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49254.html Giant Geyser cone and steam in winter. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49270.html Hot springs and snow, Upper Geyser Basin. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49267.html Upper Geyser Basin in winter. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49259.html Thermal run-off stream contrasts with snowy landscape. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49265.html Morning Glory Pool, winter. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49282.html Hiker at Morning Glory Pool, winter. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49283.html Chromatic Spring in winter. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49266.html Crested Pool in winter. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49253.html Gem pool seen from above, winter. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49321.html Hot springs detail. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49261.html Mustard Spring. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49327.html Frosted tree and thermal pool. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49325.html Sapphire Pool in winter. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49324.html Tree skeleton and thermal steam, Biscuit Basin. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49330.html Grotto Geyser at dusk. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49333.html Snow-covered West Thumb thermal basin. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49246.html Thermal stream at edge of Yellowstone Lake in winter. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49248.html Thermal run-off and snowy landscape. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49247.html Steam rising from pool in winter, West Thumb. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49244.html Colorful thermal stream and dark clouds, winter. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49249.html Thermal pool in winter, West Thumb Geyser Basin. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49243.html Park entrance sign in winter. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49231.html Forest with snow falling. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49349.html Forest in snow storm. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49348.html Pine forest in winter. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49346.html Trees on edge of Lewis Lake in winter. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49345.html Snow-covered road. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49344.html Lewis River in winter. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49230.html Snowy landscape with waterfall. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49233.html Moose Falls in winter. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49234.html Lewis Canyon slopes with burned forest, winter. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49236.html Burned tree trunks and snow, Lewis Canyon. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49237.html Lewis Falls in winter. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49238.html Lewis River valley in winter. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49240.html Lewis River and falls, winter. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49239.html Snow-covered spruce trees. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49280.html Close up of tree with snow. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49341.html Kepler Cascades of the Firehole River in winter. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49340.html Snowy forest and Kepler Cascades. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49339.html Herd of buffaloes during snow storm. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49285.html Bison moving in single file next to Firehole river, winter. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49256.html Bison following warm stream in winter. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49263.html Bisons with thermal plume behind in winter. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49315.html Bison herd on a warmer patch in winter. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49314.html Bison feeding in snow-covered meadow. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49286.html Bison crossing Firehole River in winter. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49271.html Group of buffaloes crossing river in winter. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49272.html Bisons and geyser cone, winter. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49276.html Two American bisons in winter. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49273.html American bison with snow sticking on face. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49318.html Close view of american buffalo in winter. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49275.html Snow-covered buffalo standing on warmer ground. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49313.html Snow-covered bison walking. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49288.html American bison in winter. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49277.html Coyote in winter. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49310.html Bombardier snow busses being unloaded at Flagg Ranch. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49350.html Winter tour snow coaches unloading, Flagg Ranch. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49351.html Snowcoaches and snow falling. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49352.html Bombardier snow bus. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49353.html Travelers boarding snow bus. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49232.html Snowcoaches on snow-covered road. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49235.html Couple standing in snowdrift next to snow coach. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49241.html Snowcoach and trees. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49242.html Snowmobiling on snowy day. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49347.html Snowmobilers. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49342.html Snowmobiles. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49343.html Snowmobile riders. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49323.html Tourists take pictures with entrance sign in winter. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49229.html Tourists on boardwalk in winter. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49338.html Large group of tourists in winter. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49329.html Tourists walk over snow-covered boardwalk. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49328.html Family looks at thermal pool in winter. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49326.html Cross country skiers pass Chromatic Spring. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49268.html Skiers and thermal steam. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49269.html Skiers and bisons. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49287.html Child walking with buffaloes in the distance. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49322.html Skier at the edge of thermal pool. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49332.html Photographer standing next to hot springs. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49260.html Snow coaches parked at Flagg Ranch. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49228.html Snow busses in front of Old Faithful Snow Lodge. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49335.html Bombardier snowcoaches. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49337.html Winter Snowcoaches in front of Old Faithful Snow Lodge. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49336.html Icicles, Old Faithful Snow Lodge. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49334.html Visitor Center at dusk. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49289.html New Visitor Center at night. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49291.html Old Faithful Snow Lodge at dusk, winter. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49292.html Snowmobiles parked next to Old Faithful Snow Lodge at night. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49294.html Old Faithful Snow Lodge at night, winter. Yellowstone National Park, Wyoming, USA. http://www.terragalleria.com/parks/np-image.yell49296.html