Final answer:
Mounds of glacial material deposited near ice margins are known as moraines. These features are key indicators of past glaciation events and reflect the maximum extent of glaciers, for instance, as seen with glaciers from around 1850 AD in Glacier National Park.
Step-by-step explanation:
Ridges or mounds of glacial material deposited close to ice margins are termed moraines. These features are composed of rocks and soil that have been accumulated by the action of glaciers. Moraines are distinctive in that they delineate the former extent of glaciers and can be used to infer past glaciation events.
For example, in Glacier National Park, moraines provide evidence of the maximum size of glaciers during the end of the Little Ice Age around 1850 AD. Similarly, drumlins, which are not the correct answer here, are another glacially formed feature that can indicate the direction of glacial movement. However, it is the moraines that are specifically formed from debris deposited at the edges of glaciers.