The village of Grosses Roches is located on the east bank of the Saint Lawrence River.
Grosses Roches is 90 feet [27 m] above sea level.<1>.
Time Zone: Grosses Roches lies in the Eastern Time Zone (EST/EDT) and observes daylight saving time. The time zone in French: EST- Heure Normale de l'Est (HNE), EDT- Heure Avancée de l'Est (HAE).
The elevation is an estimate for the area around Grosses Roches - it will be higher in some places and lower in others.
<2>
When there's a risk of an area code running out of phone numbers, an 'Overlay Area Code' is created that has the same geographic boundaries as the existing area code. In this case, the 418 code has been Overlayed with one of the following codes: 367 or 581. New phone numbers in the Grosses Roches area will be assigned with one of these codes: 418, 367 or 581. As a result, placing a call in the Grosses Roches area will require 10-digit dialing (where you enter both the area code and then the phone number).