WA,OR,ID,MT / Visit the source
Green Monarch Ridge
An overlooked place within Ice Age Floods: Green Monarch Ridge.
The Purcell Trench Ice Lobe originated in Canada and flowed south into Idaho, guided by the structural control of the Purcell Trench. Following the path of least resistance into the basin now occupied by Lake Pend Oreille, it was impeded by the Green Monarch Ridge forming an ice dam of the Clark Fork River and creating glacial Lake
A CLOSER LOOK
The National Park Service documents Green Monarch Ridge within Ice Age Floods.
The Purcell Trench Ice Lobe originated in Canada and flowed south into Idaho, guided by the structural control of the Purcell Trench. Following the path of least resistance into the basin now occupied by Lake Pend Oreille, it was impeded by the Green Monarch Ridge forming an ice dam of the Clark Fork River and creating glacial Lake
Use the park’s current information for access, conditions, and visitor guidance before making plans.
FOLLOW THE EVIDENCE
National Park ServiceGreen Monarch RidgeOriginal explanation based on the sources above. Images carry their own reuse terms.