A road trip of roughly 2,500 miles led me to four intriguing units of the National Park System that, while not at the top of everyone's go-to list, revealed both rich and troubling chapters of American history that likely would have faded into irrelevance without the parks that interpret their stories.

On route to an old-growth Eastern hemlock stand, we’re waylaid by a hiker keen to share her sighting of a Lady’s Slipper, a prolific orchid with a pink, pouch-shaped flower that she has confused with the rare Hooker’s orchid the park wants citizen scientists to keep an eye out for. We pause to admire ruby red teaberries and bunchberries with tiny but showy white “flowers” made up of four oval bracts, rub sweetfern to inhale its namesake scent, and gently finger the ragged lung lichen that proliferate on tree trunks.

Canadians and international visitors can visit all national historic sites, national parks and national marine conservation areas for free on Canada Day. Lockage along the Trent-Severn Waterway National Historic Site and the Rideau Canal National Historic Site, as well as at Quebec's historic canals, will also be free on July 1.

Although Bluffs Lodge, long one of our favorite national park lodging facilities, remains closed, the Bluffs Coffee Shop has been extensively renovated and is up and running for a second full season.