Trivia: The oldest known petroglyph in North America was found outside what city?
Edmonton, Alberta
Oaxaca, Mexico
Reno, Nevada
Portland, Oregon
The correct answer is Reno, Nevada
So why is this answer correct? : Somewhere between 10,000 and 15,000 years ago, Native Americans to the northeast of modern-day Reno, Nevada, carved a series of geometric patterns into stone in what is thought to be the oldest known such art on the continent. These designs include concentric circles, diamonds, and shapes that resemble trees. Geologists also found that the area where these rocks are found was once an ancient lake.