Much of the walking in the 550-acre Westerly Grills Preserve is easy, with wide flat paths, some wide enough for a truck (although motorized vehicles are not permitted). Trails follow more than a mile of the Pawcatuck River, although spots flood during times of high water. A pedestrian bridge (at the site marked “former Polly Coon Bridge” on the map) connects with trails in the Hopkington Grills Sanctuary. Other trails rise somewhat steeply to the top of “Big Hill”, a granite out-cropping with extensive views. There are additional trails extending through deep woods. The southern boundary is along the main New York to Boston Amtrak line.

In addition to riverfront and granite hills, the Preserve has diverse habitats including streams and ponds, freshwater marsh, wetland forest, upland forest, and sandy pitch pine and oak areas being managed for New England cottontail rabbit. Otter and bobcat have been seen in the Preserve.

The Preserve was selected by the Rhode Island Natural History Survey as a site for a scientific ‘Bioblitz’. Over a 24-hour period, scientists identified significantly more species of wildlife than found during any Bioblitz at other sites in Rhode Island. Thirteen species of rare plants were identified, some living nowhere else in Rhode Island.

A portion of the trail system is used as a cross-country meet course by the Westerly High School. Visiting coaches have stated that it is the best such course in either Connecticut or Rhode Island.

There are many signs of former agricultural use of the land. The Preserve includes a historic cemetery, whose residents include a veteran of the Revolutionary War.

The AllTrails website has a description and map of trails at Grills Preserve.