Shell Creek is a tributary of the Bighorn River, approximately 50 mi (80 km) long, in Wyoming in the United States. Lying entirely within Big Horn County, Shell Creek begins above the in the Bighorn Mountains. Starting at an elevation of over 11,000 ft (3,400 m), it drops to below 3,800 ft (1,200 m) as it descends the western side of the Bighorn Mountains through and enters the Big Horn Basin near Shell, Wyoming. It flows into the Bighorn River, a tributary of the Yellowstone River, just north of Greybull.