December 30, 1947 — near Pilot Hill, California. A second military aircrew, dispatched to investigate a UFO sighting, found a triangular fire burning blue-green at two of its points for nearly two hours before it went out.
THINK ABOUTIT UFO|UAP ENCOUNTER REPORT
1947: The Pilot Hill Triangular Fire
Most of this archive’s 1947 record ends with a witness’s account and nothing more to check against it. This case is different. A McClellan Field aircrew watched a flame-trailing object descend into the California hills — and half an hour later, a second crew, sent specifically to look, found a real fire burning on the ground exactly where it should have been, in a shape and color no ordinary brush fire produces. That’s rare in this archive’s entire 1947 chronology: a sighting that left something behind for someone else to find.
Date: December 30, 1947
Sighting Time: 19:25 PST (object sighted); 19:58 PST (fire first spotted); fire extinguished 21:55 PST
Day/Night: Night
Location: Object first sighted 1 mile west of Pilot Hill, California; ground fire located approximately 7 miles east of Pilot Hill, at 38°50′N, 120°53′W
Urban or Rural: Rural — forested Sierra Nevada foothill terrain
No. of Entity(s): Not Applicable
Entity Type: Not Applicable
Entity Description: Not Applicable
Hynek Classification: CE-II — Close Encounter of the Second Kind. The object was observed at close range descending toward the ground, and a physical trace — the triangular ground fire — was subsequently located and independently investigated, meeting the standard definition for a physical-effect close encounter.
Duration: Object sighting brief (not separately timed); ground fire burned for at least the 1 hour 57 minutes between its discovery and extinguishing
No. of Object(s): 1
Description of the Object(s): A high-speed, low-altitude object trailing red, green, and other colored flames, observed heading east over the hills, descending in a manner consistent with a controlled or semi-controlled descent rather than a simple crash trajectory.
Shape of Object(s): Not specified beyond its flame trail
Size of Object(s): Not specified
Color of Object(s): Red, green, and other colored flames trailing the object; the resulting ground fire burned with a distinctive bright blue-green coloration at two of its three points
Distance to Object(s): Not specified for the aerial sighting; the ground fire’s coordinates were precisely documented (38°50′N, 120°53′W)
Height & Speed: Low altitude, high speed, on a descending trajectory
Number of Witnesses: The full crew of a McClellan Field C-47 for the initial sighting; a separate, second C-47 crew specifically dispatched to investigate the resulting ground fire
Special Features/Characteristics: The ground fire’s specific triangular shape, with two of its three points emitting bright blue-green flames, is a highly unusual burn pattern inconsistent with an ordinary wildfire or brush fire, which would not typically organize into a precise geometric shape nor produce sustained blue-green flame coloration (a color more commonly associated with the combustion of specific metallic compounds, such as copper, rather than typical vegetation); the fire burned for at least nearly two hours before going out on its own, rather than being extinguished by any intervention described in the source; the sequence — aerial sighting, followed 33 minutes later by discovery of a fire at a location consistent with the object’s observed flight path, followed by dispatch of a second aircrew specifically to investigate — represents an unusually well-documented chain of cause, discovery, and independent follow-up investigation for a case this early in the UFO record.
Case Status: Unexplained
Source: Declassified FOIA military documentation
Related Cases: 1947: December UFO|UAP & Entity Sightings Archive (see also the near-simultaneous Sawtooth National Forest, Idaho sighting, one minute later)
Detailed Report
At 7:25 PM Pacific time on December 30, 1947, the crew of a C-47 transport out of McClellan Field, California, one mile west of the small community of Pilot Hill, observed a high-speed, low-altitude object trailing red, green, and other colored flames as it headed east over the surrounding hills. The crew’s specific documentation of the object’s flight direction would prove significant roughly half an hour later.
At 7:58 PM, the same crew spotted a growing fire on the ground, located approximately 7 miles east of Pilot Hill — directly consistent with the flight path of the object they had observed 33 minutes earlier. The precision of the reported coordinates, 38°50′N, 120°53′W, indicates this was treated as a serious enough discovery to warrant exact documentation rather than a rough approximation.
A second C-47 crew was dispatched specifically to investigate the fire. What they found was not consistent with an ordinary ground fire: a triangular area of fire, with two of its three points emitting bright blue-green flames — a combination of precise geometric shape and unusual flame coloration that stands well outside the range of what a typical brush or forest fire produces. Blue-green flame coloration in combustion is most commonly associated with specific chemical compounds, particularly those containing copper, rather than ordinary burning vegetation. The fire continued burning until 9:55 PM, nearly two hours after its initial discovery, before going out — with no indication in the surviving record that firefighting intervention was responsible for its extinguishing, suggesting it burned itself out.
The case survives through declassified FOIA military documentation, giving it an institutional documentary trail — an official record of both the aerial sighting and the subsequent ground investigation — that most 1947 sightings, dependent entirely on individual witness recollection, simply don’t have.
RESEARCHER’S NOTES
A Sighting That Left Evidence Behind
- On why physical trace evidence changes the evidentiary calculus: The overwhelming majority of cases in this archive’s 1947 record rest entirely on witness testimony — however credible the witnesses, there is nothing beyond their account to independently examine. This case is structurally different: a fire, at a specific documented location, with a specific unusual shape and flame coloration, that a second, independent military crew was dispatched to locate and did in fact find. That physical object — the fire itself — existed independently of anyone’s memory or interpretation, and its documented characteristics (triangular shape, blue-green flame at two points) are difficult to explain as an ordinary wildfire coincidentally occurring along the same flight path at the same time.
- On the blue-green flame color specifically: This detail deserves particular attention. Ordinary combustion of wood, brush, or typical wildfire fuel does not naturally produce sustained blue-green flame; that coloration in fire is chemically associated with the combustion of specific metallic salts, most commonly copper compounds. Whether this indicates the presence of some unusual material at the fire’s origin point, or reflects some other chemical process, this archive cannot determine from the available sourcing — but the detail itself is precise enough, and specific enough, to have likely been directly observed rather than embellished in retelling.
- On the geometric triangular shape: Wildfires spread according to fuel availability, wind, and terrain, typically producing irregular, organic-looking burn patterns rather than precise geometric shapes. A triangular fire area, specifically noted as such in the official documentation rather than described as an irregular burn zone, is itself a detail that resists an easy natural-fire explanation.
- On the near-simultaneous Idaho sighting: A separate military aircrew, roughly 400 miles away in Idaho’s Sawtooth National Forest, reported a strikingly similar sighting — a high-speed, flame-trailing object descending toward the ground — just one minute after the Pilot Hill sighting began. This archive cannot determine whether the two crews observed the same object from vastly different vantage points, two independent objects behaving similarly, or an unrelated coincidence, and states that uncertainty plainly rather than assuming a connection the sourcing doesn’t establish.
An object trailing colored flame descended into the California hills on the last Tuesday of 1947, and half an hour later, exactly where its flight path pointed, a second crew found a triangular fire burning blue-green at two of its points, for nearly two hours, until it simply went out. The founding year of the modern UFO record ends not with another account to weigh against memory and credibility, but with a fire that was actually there — documented, located, and, like almost everything else in this archive’s 1947 chronology, ultimately unexplained.
