Skip to main content
U.S. flag

An official website of the United States government

Henry Wood Elliott was a dedicated conservationist and explorer who, in 1871, helped create the first bathymetric map of Yellowstone Lake. Unlike many of his contemporaries, however, he declined to leave his name on any feature in Yellowstone. Geologists now honor Elliott’s legacy by referring to a very large explosion crater beneath Yellowstone Lake as Elliott’s Crater.

Yellowstone Caldera Chronicles is a weekly column written by scientists and collaborators of the Yellowstone Volcano Observatory. This week's contribution is from Lisa Morgan, emeritus research geologist with the U.S. Geological Survey.

Henry Wood Elliott during a geological expedition in 1870
Henry Wood Elliott during a geological expedition in 1870.  Photo by William Henry Jackson.

In 1999-2002, the U.S. Geological Survey, with support from Yellowstone National Park and Eastern Oceanics, produced the first high-resolution bathymetric map of Yellowstone Lake. One of the outcomes of this work was the discovery of a large, previously unmapped hydrothermal explosion crater in the northern part of the lake.  Subsequent research indicated that this crater, which is about half a mile across, formed about 8,000 years ago. The crater was unknown prior to the mapping not only because it is underwater, but because there are no explosion deposits from its formation on land; rather, explosion material has only been found in lake sediments.

Geologists named this impressive crater after Henry Wood Elliott, the first person to map Yellowstone Lake as part of a survey team that was an early precursor to the U.S. Geological Survey.  Henry Elliott later went on to become one of the staunchest wildlife conservationists of his time.

Henry Wood Elliott, born in 1846 in Cleveland, Ohio, was a prominent participant in the 1871 Hayden survey of the Yellowstone region—the first federally funded geological survey to explore the area that is now Yellowstone National Park.  He was a critical member of multiple surveys led by Ferdinand Hayden during 1867-1871, and he was skilled in sketching landscape panoramas and in watercolors.  Somewhat unusual for the time, however, Elliott left his name on no feature in Yellowstone.

Henry Elliott’s 1871 map of Yellowstone Lake
Henry Elliott’s 1871 map of Yellowstone Lake ( The headwaters of the Snake River, Upper Valley of the Yellowstone River, and Pelican River are shown. The area now known as West Thumb is referred to as the South West Arm on the map. About 300 lead-sink soundings of lake depth were taken in this survey; most locations where soundings were obtained are marked on this map (depth in feet). Also shown are several of the places where the Hayden survey camped as they traversed around Yellowstone Lake.

Not only did Elliott contribute significantly to documenting the features along the routes of the surveys and in Yellowstone, he also made a complete set of topographical and pictorial sketches of the shores of Yellowstone Lake from the perspective of a boat on the lake itself.  With Cam Carrington, Chester Dawes, and James Stevenson, Elliott also collected over 300 lead-sink soundings, creating the first bathymetric map of North America’s largest alpine lake in 1871.  This was quite an impressive feat, especially given the size of the lake and its waves!! 

The mapping of this large lake in a 4.5-foot-wide by 11-foot-long boat—the Annie—with a lodgepole pine as a mast, a woolen blanket as a sail, and hand-made oars was accomplished using a prismatic compass for navigation and was completed in 24 days and was remarkably accurate!  While Henry Elliott did name Frank Island, the largest of the eight islands in Yellowstone Lake, after his brother, he avoided any attempt at naming a feature after himself.    

In 1872, Elliott left the Hayden survey to journey to the Pribilof Islands in the Bering Sea of the new Alaska territory to investigate seal conditions after learning of wanton, open-sea plundering of the native fur seal population.  There, he spent years documenting the history, geography, people, and wildlife of Alaska.  He paid special attention to the flora and fauna of the Pribilof Islands, particularly the fur seal, and in doing so became a staunch defender and protector of this species.  While in the Pribilof Islands, Elliott made between two and three hundred sketches that provided convincing evidence of the need to stop the ongoing seal slaughter.  Henry Elliott probably did more to protect the Alaskan fur seal population than anyone else then or since, and he later became known internationally as a conservationist.  In 1911, he authored the first international wildlife conservation treaty of any kind: the Hay-Elliott Fur Seal Treaty.  Again, quite an accomplishment for the time!

Elliott’s dual commitment to science and conservation, and his uncharacteristic (for the time) modesty, are commendable. Elliott’s Crater serves to memorialize the largely unsung and important contributions of Henry Wood Elliott.

Painting by Henry Wood Elliott (1846-1930), Yellowstone Lake, 1871, watercolor.
Painting by Henry Wood Elliott (1846-1930), Yellowstone Lake, 1871, watercolor (Phoenis Art Museum).  The view is from northern Yellowstone Lake looking to the south.  In the foreground, one can see the Annie in the northern lake and the three largest of the lake’s islands: Stevenson Island, with Frank Island and the smaller Dot Island behind.  Flat Mountain and Mount Sheridan are in the background on the southern side of the lake, with the Tetons in the far background.  To the left, one can see the Promontory and, continuing counterclockwise, Steamboat Point, Lake Butte, the wall of the Mary Bay explosion crater, the Absaroka Range in the distance, and Storm Point.

Get Our News

These items are in the RSS feed format (Really Simple Syndication) based on categories such as topics, locations, and more. You can install and RSS reader browser extension, software, or use a third-party service to receive immediate news updates depending on the feed that you have added. If you click the feed links below, they may look strange because they are simply XML code. An RSS reader can easily read this code and push out a notification to you when something new is posted to our site.