rating: +98+x
Item#: 4997
Containment Class:
Secondary Class:
Disruption Class:
Risk Class:


An outpost of Provisional Site-72, tasked with monitoring and reporting unusual seismic activity in the Madison Junction area of Yellowstone National Park.

Special Containment Procedures: At present, direct containment of SCP-4997 is not possible. Secondary containment methods are limited to studying SCP-4997 to gain a better understanding of its behavior and the development of methods to control or neutralize it. Research is to be conducted primarily at Provisional Site-72, at Yellowstone National Park. Because the caldera is situated in a U.S. National Park, no realistic way of keeping civilians out of the area without arousing suspicion is possible; to compensate, civilian activity within the caldera is to be monitored and acted upon as necessary. Although only the Foundation and a select few GoIs possess technology capable of detecting SCP-4997 in its current position, any information indicating a third-party discovery of it is to be suppressed and its source investigated.

Neutralization of SCP-4997 is of extreme priority due to its potential to cause catastrophic damage to the geological integrity of the Yellowstone Caldera, a worldwide economic depression, and an ßK-Class "Lifted Veil"1 scenario. Authorization from the O5 Council for neutralization via anomalous means is pending has been approved.

In the event that SCP-4997 successfully breaches the Earth's crust at its current location, all personnel and civilians within 100 kilometers of the point of exit, thereafter designated Point-Γ, will be considered lost. Point-Γ and the affected area surrounding it, designated Area Φ, is to be sealed off from as much outside attention as possible through any means necessary. Once SCP-4997 has emerged, all Foundation assets within 200 kilometers of Area Φ are to be utilized to neutralize the subject.2 Should these efforts fail, all Foundation personnel worldwide are to prepare for an ßK-Class "Lifted Veil" scenario.


SCP-4997's historical breaching locations and volcanically-affected areas.

Description: SCP-4997 is a massive organism currently located somewhere in the magma chambers beneath the Yellowstone caldera in Wyoming, USA. Likely resembling a large reptilian, estimates put its size anywhere between 15 to 30 kilometers long by 3 kilometers wide. Additional data suggests SCP-4997 possesses at least 300 limbs along its body that would theoretically enable terrestrial locomotion if on land. SCP-4997 is thought to be roughly 16 million years old and to have primarily resided somewhere between the crust and asthenosphere underneath the North American tectonic plate near the border of Idaho and Wyoming for all of its known history.

Judging from the geological record of the Snake River Plane, SCP-4997 is believed to undergo a semi-regular cycle of dormancy and activity, typically "sleeping" until awakening during so-called "breaching" events every few million years. During these events, SCP-4997 will breach the Earth's crust, causing catastrophic localized damage to the area before later returning to the Earth's interior; these breaches generate drastically increased volcanic activity in the surrounding areas. New breaches have always occurred within 200 kilometers of the previous emergence point, and SCP-4997 is not thought to have ever emerged from a previously breached site.

Foundation biologists believe this behavior to be feeding-oriented, however the collective flora and fauna surrounding historical emergence points should not be even remotely enough food to sustain an organism of this size. Additional theories claim it may be photosynthetic or feed off of some other resource absent underground. Investigations into SCP-4997's motivation for breaching are underway due to their potential applications for neutralization.

Discovery: SCP-4997 was first discovered on 9/12/16 by Foundation personnel planted at the Yellowstone Research Center who had augmented the Center's research equipment with Foundation technology to attempt to detect an unrelated anomaly, which was at the time believed to be hiding underground somewhere nearby. The agents noticed unusual readings in the magma chambers beneath the Park and pursued further study which confirmed the existence of what is now designated SCP-4997. Provisional Site-72 was erected in the Park to further the study of SCP-4997 the following year.

In the summer of 2017 a Site researcher proposed SCP-4997's breaching behavior, citing the geologic record of the Snake River Plane in a paper to the Site Director, Dr. Jaskes. Further investigation into the proposal using [DATA REDACTED DUE TO INSUFFICIENT SECURITY CLEARANCE] confirmed with 98.76% accuracy that the researcher was correct in her inquiry.3 Following this discovery, the Site's primary objective was changed to focus on the neutralization of SCP-4997.

SCP-4997 Historical Activity Log:

Breach Point Notes Approximate Occurrence
Owyhee-Humboldt Caldera First known site of SCP-4997 activity. 16 MYA4
Bruneau-Jarbridge Caldera Ensuing eruption terminates surface life within a 160km radius. Unusually high, possibly anomalous amounts of silicate-rich, rhyolitic magma detected in pyroclastic flow beds. 15-13 MYA
Twin Falls Caldera Very similar to the Bruneau-Jarbridge eruption, in addition to fine ashfall spreading to distances greater than 1,000 kilometers away. 12-10 MYA
Hagerman Caldera Occurred within an extremely short time of the occurrence of the Picabo Caldera, which would be formed soon after; motivation for SCP-4997’s apparent early breaching remains unknown. 12-8 MYA
Picabo Caldera Occurred within an extremely short time of the formation of the Hagerman Caldera; motivation for SCP-4997’s apparent early breaching remains unknown. 10-8 MYA
Heise Caldera Occurred much earlier than anticipated based on previous breaching patterns. Could indicate an acceleration of time between dormant and active periods. 6-4 MYA
Yellowstone Plateau The most recent breaching event to date. Taking the possible breaching pattern’s acceleration and recent geological activity into consideration, SCP-4997 could breach within the next 50 years. 2.1-0.6 MYA

Addendum 4997-A: 8/3/18 marked the beginning of a gradual increase in the intensity and frequency of seismological activity in the vicinity of the Yellowstone Caldera. Taking the historical rate at which SCP-4997 has emerged into account, it can be inferred that SCP-4997's current dormant period is ending and SCP-4997 could be preparing to breach. It is unknown when exactly it will occur, but according to additional research it could be as soon as 2025.

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