Search for rare RI State Rock on a hike in Cumberland

  • Access: From the south, take Route 99 from the intersection of Route 295 / Route 146. At the end of Route 99, turn right onto Mendon Road. Drive half a mile to a dollar store on the left. The start of the trail is to the right of the parking lot.
  • Parking: Many spaces in the lot.
  • Dogs: Allowed, kept on a leash.
  • Difficulty: Easy on flat trails with small hills.

CUMBERLAND – Two prominent families, the Blackalls and Ballous, farmed, raised cattle, rode horses and lived for years on a rural expanse of woods and low hills in the northern part of town.

Over the decades, urban sprawl, comprising apartments, houses, a commercial strip and a business park, has crept into fields and forests.

But local environmentalists managed to save 184 acres Blackall / Ballou Reserve. A thriving natural oasis, the sanctuary offers family trails and reminders of old farmhouses, including miles of stone walls that separated pastures, woodlands, and orchards.

A map of the trails of the Blackall / Ballou reserve in Cumberland

The reserve also has a unique feature: large piles of small rocks, including chunks of Cumberlandite, the official rock of the state of Rhode Island. It’s fun trying to find a specimen, but you need a magnet. (More on that later.)

Outdoor fun:From beaches to trails, there is plenty to do in RI this summer

RI walk:Cultural connections on a road trip in the Berkshires

There are several entry points to the public reserve. I started onto a path at the south end of the property, just off the Dollar Store parking lot on Mendon Road, where the Bennys were.

The start of the trail is marked by nesting boxes and 15 gently sloping steps.

A blue birdhouse marks the start, followed by a set of 15 wooden-lined stairs leading to a series of wetlands. Depending on how much rain has recently fallen, the lowlands may be dry enough or swampy enough to attract insects in warm weather. There are several wooden walkways and plank bridges that cross muddy areas covered in stinking ferns and cabbages.

RI walk:Hollywood Factor on the Hopkinton Trail

RI walk:A green getaway in the heart of Providence

At an intersection I went right onto the wide, light blue trail which remains mostly flat and winds under oak and maple trees, with some beech, pine and birch trees. The trail then climbs a small hill along some outcrops, with private property on the right. I heard songbirds in the bushes and could smell the honeysuckle.

A boardwalk and planks cross some low areas.

After about half a mile the path exits at another starting point with signage on West Wrentham Road. The trail turns west, passes a few more nesting boxes, and continues under a power line, with wildflowers growing on the cleared ground, before entering the woods.

The path then comes to a crossroads. I turned right on a red connecting trail that went up for a short distance before joining a yellow loop. I turned right and quickly noticed a whitewashed trail heading east that was possibly a horse trail that leads to another trail on Old Wrentham Road where the Blackall family had a farm.

A series of nesting boxes line the power lines that cross the Blackall / Ballou reserve.

I stayed on the yellow trail and circled around the north until I reached the end of the property where I found a large pile of stones that were too small to build walls but probably have been cleared from fields by farmers. I had read that some of the stones were cumberlandite, a rare mineral rich in iron and titanium found only in large concentrations over four acres at Cumberland and in traces scattered throughout the Bay of Watershed. Narragansett.

A sample of Cumberlandite, a rare magnetic mineral found only in high concentrations over four acres at Cumberland.

Cumberlandite, originally called rhodose, formed 1.5 billion years ago when a small volcano fused 24 minerals and molten rock. The Nipmucks believed the rock to be sacred, and early settlers mined it in a quarry just north of the reservation. At a nearby steel plant, the ore was made into farm tools, weapons, cannons, and cannonballs during the War of Independence, but the casts were of poor quality and prone to cracking.

In 1966, the General Assembly declared Cumberlandite rock the state’s official.

Several streams cross the yellow trail at the north end of the reserve.

Due to its large amounts of iron, cumberlandite is slightly magnetic. I picked up several charcoal gray rocks with white spots from the pile and ran a magnet over them. Eventually, one of the samples stuck to the magnet.


I pocketed the rock and continued on the yellow trail that turned south and crossed a narrow stream, one of three that I came across that are easy to cross. On the right, beyond the stone walls and through the trees, I could see many buildings.

The western half of the Blackall property has been sold and developed as Highland Corporate Park for CVS and other companies. The eastern half has been kept as an open space.

Miles of stone walls that once separated pastures, fields and orchards follow the paths.

I followed the trail along a downhill ridge line, coming back to the red connection trail that brought me back to the blue loop. I went right and crossed a marked gas pipeline and power line again and followed the trail on a slight jog west to another trailhead. The path then plunged into the woods and skirted the banks of a small, calm pond that could have been a watering hole for the cattle. From there, I went back to where I started.

RI walk:A hiker’s guide to rediscover their condition (and themselves)

In total I hiked 3.5 miles on well marked trails maintained by the Cumberland Land Trust including 0.3 mile on the entrance trail and 1.39 mile on the blue loop. 0.7 miles on the red connector and 1.15 miles on the yellow-blazed loop.

A quiet and partially hidden farmhouse pond can be found at the western end of the property.

After the hike I drove north on West Wrentham Road and took a left on Elder Ballou Meeting House Road to a historic graveyard. I walked a hundred yards on a path behind the cemetery and found the abandoned quarry, with outcrops of cumberlandite.

It seemed like a fitting end to a memorable morning hike and I came home with a memento in my pocket to remind myself of it.

Trail Council

John Kostrzewa will discuss Walking Rhode Island and recommend easy and moderate trails during a presentation on August 3 at the Cranston Public Library. For more details go to

John Kostrzewa

John Kostrzewa, former associate / corporate editor at Providence Journal, greets emails at

About John Crowder

Check Also

Billy Corgan and friends go wild in Highland Park for a good cause

HIGHLAND PARK, Ill. — Smashing Pumpkin frontman and Highland Park resident Billy Corgan took the …

Leave a Reply

Your email address will not be published.