Possible Clues:

• Ages getting to North-Eastern national park
• River with falls in Wyoming
• Chicken satay and tikka starters at lunchtime, current in the western US
• Topaz, perhaps, found in park
• Topaz may be found in park
• US river where chicken put to death
• Oldest national park
• Most of this national park is in Wyoming
• Zircon, say, found in American park?
• The first U.S. National Park