Saturday | April 11, 2026

Led by paleontologst Joshua Lively

If you took a time machine 85 million years in the past, Green River would be at the seafloor, hundreds of feet below the surface. While dinosaurs were walking on the land near what is now the Wasatch Plateau, marine life was teaming in the shallow seas of eastern Utah.

Join Dr. Joshua Lively for a tour of the Cretaceous Mancos Shale and a look at the life inhabiting this ancient sea, including ammonites and giant clams! We will take a short trip outside of town to see these fossils in the field and learn what they tell us about Cretaceous seas.

Ocean-Front Property in Green
River: Giant Clams of the
Mancos Shale

Presented by Prehistoric Museum, USU-E

This half-day field trip stays close to Green River and is excellent for folks who enjoy spending an afternoon out in the dust and have an interest in marine life of the Cretaceous.

See below for important trip information.

  • Participants must drive their own vehicles.

    Vehicles with somewhat higher clearance, such as a Subaru Outback or greater, are required to safely navigate routes on this trip.

    If there has been recent heavy rain, this trip may be cancelled.

  • Water, snacks, camera.

  • Josh Lively, PhD
    Paleontologist

    Joshua Lively, PhD, is the Curator of Paleontology at the Prehistoric Museum in Price, Utah. He earned his master's from the University of Utah where he studied Cretaceous turtles, and a PhD from The University of Texas at Austin, where he focused on mosasaurs and other Cretaceous marine life.

How to Sign Up

Fossil fragments in the Mancos Shale. Photo courtesy Mike and Gia McHue.