Indiana's Calumet Trail is a nine-mile journey connecting two noteworthy geological features: Mount Baldy, a sand dune over 120 feet tall in Town of Pines, and Cowles Bog, an ancient marshland in Dunes Acres. In between, you'll enjoy a peaceful hiking/biking path following utility rights-of-way and a light rail line. Cross-country skiers and snowmobilers use the trail in winter, so you could even try your hand at mushing if there are any sled dogs in your pack.
Highway 12 and local communities are accessible from many points along the trail, so help is nearby if you need it. The journey still feels peaceful, though, even isolated. It's a good thing you'll bring your BFFs for company! Just make sure they stay on-leash, since deer and other four-legged visitors are also known to hang out on the Calumet Trail.
You won't find restrooms or running water at the eastern trailhead near Mount Baldy. However, there's a furrific reason to focus your visit here anyway: The option to cool off after your hike at the dog-friendly Mount Baldy Beach in the Indian Dunes National Lakeshore! The beach parking area on Highway 12 is less than a mile from the eastern trailhead. (Note that hiking on Mount Baldy itself is by special permit only; keep Fido and Fifi close to protect this fragile ecosystem.)
Toss a towel or three in your car even if you plan to skip the beach. Large puddles form along the trail (you're near a bog, after all) so your pups may attempt to bring home some souvenir mud from the Calumet.
Need more trail for your insatiable pups? No problem. The Calumet connects to several other hiking routes. That includes the easy Great Marsh Trail and Calumet Dunes Trail, plus the 8-mile Glenwood Dunes Trail and extensive Indiana Dunes State Park trail system, all of which have turn-offs from Calumet.
The only trailside restrooms are portable toilets in the parking area at the western trailhead. Here, you can also sniff out the Cowles Bog Trail System and the Porter Brickyard Trail, too, which share the parking lot. Bird dogs will enjoy pointing out the plentiful songbirds and shorebirds that live in these lush wetlands.