Fossil Hunting at Bayanzag (Flaming Cliffs), Mongolia

Bayanzag, Mongolian for "abundant in saxaul shrubs", is a striking band of orange-red sandstone cliffs about 100 km northwest of the South Gobi aimag capital of Dalanzadgad. The American paleontologist Roy Chapman Andrews of the American Museum of Natural History gave them the nickname "Flaming Cliffs" during his Central Asiatic Expeditions of 1922–1925. It was here in 1923 that George Olsen of Andrews's team collected the first dinosaur eggs ever identified as such, originally attributed to Protoceratops and later reattributed to Oviraptor.

The cliffs continue to produce internationally studied Late Cretaceous fossils today, including beautifully articulated Protoceratops andrewsi and Velociraptor mongoliensis skeletons. The famous "Fighting Dinosaurs" specimen, a Velociraptor locked in combat with a Protoceratops, came from nearby Tugrugeen Shireh. Unlike most marquee fossil sites, Bayanzag is open and informal: visitors can walk freely along the cliff edge, and fragments of bone and eggshell still weather out onto the slopes.

This guide covers what you'll see, how to reach Bayanzag, and the legal and ethical rules around handling fossils in Mongolia.

Location and Directions

Bayanzag is in Bulgan sum (district) of Ömnögovi (South Gobi) Province, Mongolia, roughly 100 km northwest of Dalanzadgad.

Directions to Bayanzag

Almost all visitors reach Bayanzag as part of a multi-day Gobi tour from Ulaanbaatar. The fastest route is to fly Ulaanbaatar–Dalanzadgad (about 1.5 hours) and then drive west by 4×4 (roughly 2–3 hours, much of it on unpaved tracks). Driving the full distance from Ulaanbaatar to Dalanzadgad takes 1–2 days each way.

Most tours stay in nearby ger camps a few kilometres from the cliffs (Three Camel Lodge, Gobi Erdene, and similar). Independent visitors should hire an experienced Mongolian driver and guide. Navigation in the Gobi is by GPS and local knowledge, road signs are minimal, and breakdowns or sandstorms can be serious. Spring (April–June) and autumn (September–October) are the most pleasant seasons. Summer is hot and dusty, and winter is brutally cold.

There is no entry fee or fenced boundary at Bayanzag. Visitors simply walk in. Sunset views from the cliff edge, looking out over the descending desert toward the saxaul forest, are the iconic Bayanzag experience.

What Fossils You'll See

The Djadochta Formation at Bayanzag preserves a Late Cretaceous (Campanian, roughly 75 to 71 million years ago) arid dune-and-interdune environment, with frequent sandstorm deaths and dune collapses producing fully articulated three-dimensional skeletons. Unlike the more common flattened compressions of lacustrine deposits, the Djadochta fossils are preserved as articulated three-dimensional skeletons in sandstone, a preservation mode that has produced some of the best-preserved dinosaur specimens in the world.

The cliffs and adjacent slopes routinely yield surface scatter of bone fragments and dinosaur eggshell pieces, visitors walking with a guide will be shown weathered Protoceratops limb bones, fragments of the curved white eggshell Elongatoolithus (the egg type now attributed to oviraptorids), and occasional dinosaur teeth still in place in the eroding sandstone. By far the most abundant dinosaur at Bayanzag is the small ceratopsian Protoceratops andrewsi, a 1.8-metre-long sheep-sized herbivore with a parrot-like beak and a small bony neck frill. Protoceratops skulls and skeletons have been recovered by the hundreds across the Djadochta outcrop belt, and the species is interpreted as the dominant herbivore of the Djadochta ecosystem.

The famous small predator Velociraptor mongoliensis, a 2-metre-long feathered dromaeosaur whose Hollywood depiction in Jurassic Park made the species globally famous (though the Hollywood version is far larger than the real animal), is the second-most-common dinosaur at the site. The Tugrugeen Shireh locality immediately north of Bayanzag produced the iconic 1971 "Fighting Dinosaurs" specimen, in which a Velociraptor and a Protoceratops were preserved in combat at the moment they were buried alive by a collapsing dune. The specimen is now displayed at the Mongolian Central Museum of Mongolian Dinosaurs in Ulaanbaatar.

The oviraptorid Oviraptor philoceratops, originally described in 1924 from a skeleton found brooding on a nest of eggs at Bayanzag, was for decades misinterpreted as an "egg thief" caught in the act, until similar nests with embryos inside in the 1990s revealed the eggs were the oviraptor's own and the adults were actually brooding their young. Other dinosaurs documented from the Djadochta and adjacent Ukhaa Tolgod localities include the alvarezsaur Mononykus olecranus (with strange single-clawed forelimbs), the ankylosaur Pinacosaurus grangeri, the troodontid Saurornithoides mongoliensis, the small ornithischian Avimimus, and the parrot-faced Psittacosaurus.

Non-dinosaur fossils matter just as much. Small multituberculate mammals (Catopsbaatar, Kryptobaatar) and eutherian mammals (Zalambdalestes lechei, Kennalestes gobiensis), both critical for understanding Late Cretaceous mammal evolution, have been recovered as articulated skulls and partial skeletons. The carnivorous squamate lizard Estesia mongoliensis and several smaller lizards are present. Excellent embryos in eggs, including embryos of Oviraptor, troodontids, and Protoceratops, have been recovered from in-situ nests, providing distinctive developmental data on dinosaurs at the moment of hatching.

"In 1922, American paleontologist Roy Chapman Andrews led an expedition here and discovered the first dinosaur eggs ever found in the world, along with hundreds of skeletons of species such as Protoceratops and Velociraptor." Three Camel Lodge

Geologic History

During the Late Cretaceous (Campanian Stage, about 75 to 71 million years ago), what is now the Gobi Desert was a hot, arid inland basin between rising mountain ranges, with the Pacific subduction-driven Sino-Korean Block to the southeast and the rising Altai-Sayan and Khangai mountain belts to the north and west. The intracontinental position kept the basin far from maritime moisture sources, and prevailing atmospheric circulation produced an arid to hyperarid climate analogous to the modern Gobi or Sahara. Extensive dune fields with interdune ponds and ephemeral streams dominated the landscape. Small isolated water bodies supported limited vegetation and the dinosaurian and mammalian fauna we know from the Djadochta Formation.

The Djadochta Formation itself is divided into the lower Bayn Dzak Member (the principal fossil-bearing unit at Bayanzag) and the upper Tugrugeen Member. Both consist of red-orange, iron-rich, fine to medium aeolian sandstones with thin interbedded silty palaeosols representing brief wet intervals between dune-forming episodes. Sudden sand dune collapses, triggered by heavy local rainstorms or by undermining wind erosion, and large coordinated sandstorms buried entire animals alive in the dune-collapse and dune-toe positions where they were preserved as articulated skeletons. The classic "Fighting Dinosaurs" specimen captures a Velociraptor and Protoceratops engaged in combat at the moment they were entombed by a collapsing dune, with the Velociraptor's sickle claw still embedded in the Protoceratops's throat.

The red-orange iron-rich sandstones, coloured by oxidised hematite from intense Cretaceous chemical weathering, gave the cliffs their characteristic glow at sunrise and sunset and inspired Roy Chapman Andrews's "Flaming Cliffs" nickname. Continued aridity through the Cenozoic protected the deposits from the chemical weathering and burial that would otherwise have destroyed them, and modern wind erosion of the cliff faces continuously exhumes fresh fossils. The cliffs retreat by an estimated 1 to 3 centimetres per year, exposing new bone surfaces every season.

The Bayanzag dinosaur fauna was first discovered by the Roy Chapman Andrews–led American Museum of Natural History Central Asiatic Expeditions of 1922 to 1925, which produced the first dinosaur eggs ever identified, the type specimens of Velociraptor and Oviraptor, and most of the original Protoceratops skeletons. Polish-Mongolian expeditions of the 1960s and 1970s (Zofia Kielan-Jaworowska and Rinchen Barsbold) and the more recent American Museum-Mongolian Academy of Sciences expeditions of the 1990s and 2000s (Mark Norell, Michael Novacek, and Rinchen Barsbold) reopened the area to modern scientific work and dramatically expanded the known faunal list, especially with finds at the adjacent Ukhaa Tolgod and Tugrugeen Shireh localities.

How Bayanzag Came to Be Protected

Bayanzag is part of the Cretaceous Dinosaur Fossil Sites in the Mongolian Gobi UNESCO World Heritage Tentative List (added in 2014) and is a designated protected area within the Mongolian state under the Mongolian National Heritage law. All vertebrate fossils in Mongolia are state property. Export of fossils is illegal and has been aggressively enforced since the 2010s, with several high-profile international prosecutions of trafficked Mongolian specimens (most famously the 2012 repatriation of a Tarbosaurus bataar skeleton from a New York auction). Visitors should under no circumstances buy fossils from local vendors, they are illegally collected and cannot be legally exported.

Collecting Rules & Regulations

Is Fossil Collecting Allowed?

No. All vertebrate fossils in Mongolia are state property. Export of fossils is illegal and aggressively enforced, with several high-profile international prosecutions of trafficked Mongolian specimens.

Key Points:

Free walking access. No entry fee, no fenced boundary
No collection, hammering, or removal of any fossil or rock, including small bone or eggshell fragments
Stay back from the cliff edge. The soft sandstone undercuts and collapses
Hire an experienced driver and guide for any Gobi travel
Carry plenty of water, sunscreen, and dust protection
Do not buy fossils from local vendors, they are illegally collected and cannot be legally exported

Bayanzag (Flaming Cliffs) Fossil Guide