Walking the Canal towpath towards Georgetown, one comes across a sign that is literally almost in the Potomac River, reading in urgent letters, “Deadly undertow, Get to shore.” But this undertow is only one of the Potomac’s lethal actions; it is also capable of serious flooding causing immense damage. In fact, it was a series of such floods that propelled the Chesapeake and Ohio Canal to change course, from its historic role of commercial transport to one of becoming a conduit for wildlife, and entering the National Park System as a National Historical Park.

Straddling the highway at the eastern entrance to Riding Mountain National Park, a truss bridge made of hand-hewn logs and local stones featuring turret-like cupolas set on twin kiosks transports you to the 1930s and the early days of Canada’s national parks system. The gateway makes some people feel like they’re living the scene from Jurassic Park when the awestruck main characters first pass through a massive gate to an island theme park.

The Southwest is nowhere near as famous Ring of Fire that fuels coastal Pacific volcanoes, but it does have a history of eruptions that the National Park Service interprets.

Nova Scotia’s Sable Island National Park Reserve is a magnet for those who love tough little equines.