The Red Gulch Dinosaur Tracksite in the Big Horn Basin, Wyoming, USA, is a relatively "new" tracksite having "interesting" tracks, invertebrate trace fossils, and geologic setting. I say "interesting" because "spectacular" might be an overstatement and because the study is just beginning. The U.S. Bureau of Land Management (BLM) has contracted for Brent Brighthouse and Beth Southwell (University of Wyoming) to oversee a study beginning about 15 June 1998 (Anonymous, 1998).
The tracks are in a thin oolite intercalated in thick, typical gray-green shales of the Middle Jurassic Sundance Formation. The bed makes up a dip slope and is washed clean in an arroyo. The BLM claims approximately 40 acres of exposure. The surface of the trackway layer is partly rippled and partly rough. I interpret the rough surface as algal mat.
Erik Kvale (Indiana Geological Survey and Indiana University) found the site and will do sedimentology and mapping. Michael Brett Surnam (National Museum of Natural History) will study body fossils. I saw numerous Gryphaea, some Ostrea?, some Pentacrinus stalk plates, and rare echinoid plates.
Allen Archer (Kansas State University) will describe invertebrate trace fossils. I saw the largest Diplocraterion "pits" I have ever seen. They are pits about 3 cm wide, 15 cm long, and 5-10 cm deep, clay-filled from the overlying unit, and with bulbous ends in the oolite substrate. Because of their size, I presume they were made by fossorial shrimp. At another site I found a small starfish trace.
Gary D. Johnson (Dartmouth College) will study chronostratigraphy and mapping. Michael Nause (South Dakota School of Mines) will do GIS mapping.
Brent Brighthouse and Beth Southwell (University of Wyoming) will study the vertebrate tracks. I had the impression they were made by essentially one size of theropod and mostly going southeast or northwest. The tracks appeared to be in a moderately firm oolite because some flow-back renders the tracks poorly defined.
The site is easily accessed per the BLM "from May through October using a high clearance, two-wheel-drive vehicle." The road is gravel and a car could easily make it most of the time.
Go ten miles east of Greybull or four miles west of Shell, Wyoming, on U.S. Highway 14. Take Red Gulch/Alkali National Back Country Byway (signs were in place) going south 5.2 miles from turnoff. The site is visible with heavy log guardrails. The best part we saw was north of the parking area where the culvert comes under the road into the arroyo. The best time to go is early morning when the sun is low to the surface (about 7:00 a.m.).
Dinosaur bones are present on Potato Ridge to the west and mammal bones and teeth are present in the Willwood variegated beds north and east of the site.
The BLM wants public input on how the site should be developed. They have a single page flier and can be reached at: Bureau of Land Management, Worland District Office, 101 South 23rd, Worland, WY 812401, USA; telephone (307) 347-5100.
Anonymous 1998. Making tracks. Geotimes, 43(6): 9.