The Yellowstone Overhead Sounds

Summary

From the 1870s onward, parties travelling near Shoshone Lake and Yellowstone Lake reported a sound that seemed to pass overhead across the sky, lasting from a few seconds to half a minute, heard most often on still bright mornings shortly after sunrise. It was likened to a harp struck lightly high above the trees, to telegraph wires, to bells and to a swarm of bees.

Two research scientists published first-hand accounts in 1893, one in a United States Fish Commission bulletin and one in Science. Their descriptions agree closely. No source the Registry found records an instrument being pointed at the phenomenon or a recording being made, and the last published attempt at a mechanism was made in 1937.

What is documented

Where it was heard. Hiram Martin Chittenden, a captain in the Army Corps of Engineers, wrote in The Yellowstone National Park: Historical and Descriptive (1895) that the sounds "have long been noted by explorers, but only in the vicinity of Shoshone and Yellowstone Lakes". He called the phenomenon "a most singular and interesting acoustic" one, consisting of "strange and indefinable overhead sounds", which "seem to occur in the morning, and to last only for a moment". The term this record uses is his. Chittenden did not hear the sounds himself. He presented them "from the pens of those who have given some study to these strange sounds", quoting Forbes and Linton, and closed: "No rational explanation has ever been advanced for this remarkable phenomenon."

What it sounded like. Stephen A. Forbes, writing in 1893, likened it to "the vibrating clang of a harp lightly and rapidly touched high up above the tree tops", or to "the sound of many telegraph wires swinging regularly and rapidly in the wind", and elsewhere to "faintly heard voices answering each other overhead". Edwin Linton, the same year, compared it to "the echo of bells after being repeated several times" and to "the humming of a swarm of bees", and is quoted describing "a rather indefinite, reverberating sound, characterized by a slight metallic resonance". Frank H. Bradley of the Hayden survey, the earliest named witness, is quoted describing "a curious sound, between a whistle and a hoarse whine" heard while his party prepared breakfast on the lake shore.

Forbes, 1893. Stephen A. Forbes published his account as a footnote on page 215 of a preliminary report on the aquatic invertebrate fauna of the park, issued in the Bulletin of the United States Fish Commission for 1891 on 29 April 1893. He first heard it at Shoshone Lake "while out on the lake in the bright still morning", and heard it repeatedly, and most often, at Yellowstone Lake. Each episode lasted from a few seconds to half a minute or more. It came on still bright mornings soon after sunrise and was loudest then, though he once heard it faintly at noon in a stiff breeze.

Linton, 1893. Edwin Linton published a note titled "Overhead Sounds in the Vicinity of Yellowstone Lake" in Science on 3 November 1893. The note is quoted as recording his first hearing: "The first time I heard them, or it, was on the 22d of July, about 8 a.m. on Shoshone Lake." Of its movement: "It appeared to begin directly overhead and to pass off across the sky, growing fainter and fainter towards the southwest." The passage Chittenden reproduced in 1895 describes a sound that "seemed to begin at a distance, grow louder overhead". His guide, Elwood Hofer, is quoted calling it "the most mysterious sound heard among the mountains", and a member of his party describing "a twisting sort of yow-yow vibration".

How it moved. Forbes described a sound that "draws rapidly near with louder and louder throbs of sound" and then "dies away in the opposite direction", or wanders irregularly about. Linton’s first hearing passed overhead and died away to the southward. Neil Miner, in 1937, recorded a sound that seemed to come from above the north end of the lake and moved horizontally south over the water for about ten seconds. All three describe a sound that travels overhead rather than one that stands in one place. Chittenden, summarising the published accounts in 1895, gave "the general direction noted by writers" as north to south.

What the witnesses ruled out at the time. Forbes recorded and dismissed the explanations travellers offered him, among them atmospheric electricity, the whistling of ducks’ wings, and the noise of a geyser carrying. He wrote that "No scientific explanation of this really bewitching phenomenon has ever been published." Miner separately ruled out birds for his own observation on the ground that none were visible, the morning being clear and calm.

The only documented in-park investigation. Neil Miner, a ranger naturalist, published "Yellowstone’s Mystery Sounds" in Yellowstone Nature Notes for May and June 1937, describing a sound he and the late assistant naturalist Crowe heard one September morning. It is the last documented attempt at a mechanism. The article contains no measurements and labels its own suggestion "a possible explanation".

The witnesses, named. The documented record names six people who heard it: Frank H. Bradley, Edwin Linton, Stephen A. Forbes, Elwood Hofer, Neil Miner and Crowe. Chittenden, whose book is the best-known account, reported the observations of others. Two of the six, Forbes and Linton, were working research scientists who published their accounts in a federal bulletin and in Science, which is what separates this record from a travellers’ tale.

Where it stands with the park. The National Park Service’s own public account, posted in December 2013 and last updated in April 2025, quotes Chittenden, proposes no explanation, and states that no one has been able to conclude what causes the sound. Lee Whittlesey, the park’s retired historian, is cited across these accounts. Yellowstone Gate reports that he has lived near the park for more than thirty-five years without hearing the sound, and he has said that reports dwindled after the mid-1960s.

Two dates that are not settled. Sources disagree on the year of Bradley’s hearing, giving 1871 or 1872, and on the year of Linton’s 22 July hearing, giving 1890 or 1892. The Registry could not open either underlying text and does not pick between them. Miner gives no year at all for his September observation.

Leading explanations

Aerial echoes (Forbes, 1893; hypothesis, untested). Forbes wrote that "It seems to me to belong to the class of aerial echoes", while conceding in the same footnote that this did not account for the origin of the sound being echoed. It names a mechanism of transmission and leaves the source open.

Horizontally moving air vortices (Miner, 1937; hypothesis, untested). Miner suggested that day and night temperature differences, together with air draining down from the peaks around the lake, set up currents in the lower atmosphere, and that "horizontally moving whirlpools of air, similar to those one often sees" on the lake surface could travel fast across the water and produce the sound as they dissipate. He presents an analogy and a single observation, with no measurement, and calls it a possible explanation.

Small earthquakes amplified underground (1930; hypothesis, untested). An article in Popular Science in 1930 is reported to have proposed minor seismic events whose sound is magnified in underground cavities acting as sound boxes. The Registry could not open the article and names no author for it.

A temperature inversion carrying distant sound (hypothesis, untested). Warmer air lying above cooler air over the lake would change how sound travels, and could make a distant source seem close and overhead. This is attributed in secondary accounts to work with a park meteorologist, but the Registry could not reach a primary publication, and does not state the names the secondary sources give.

Electricity, ducks or geysers (rejected, 1893). The explanations offered to Forbes by travellers. He dismissed each on the spot. Miner later ruled out birds for his own observation.

Current status

Unsolved. The phenomenon is well attested and unexplained, which is an uncommon combination and the reason this record exists. Two scientists published independent first-hand accounts in 1893 that agree it came in the morning, travelled overhead across the sky and had a ringing, resonant quality, and a third account in 1937 matches them. No source the Registry found records any explanation being tested. The last published mechanism is eighty-nine years old and contains no measurements, and the National Park Service states that no cause has been concluded. No source the Registry retrieved mentions an audio recording. A calibrated recording carrying a timestamp, a bearing and a spectrum, ideally from an array able to locate the source, would change this record, as would a modern infrasound or seismic-acoustic study correlating events with local seismicity, thermal activity or boundary-layer soundings.

Last reviewed: November 2026. Records are provisional. Where the evidence changes, the entry changes. Found an error? Tell us.