Envisioned as a "stream valley park" to protect Baltimore's watersheds, including the Gwynns Falls, from overdevelopment and to preserve their natural habitats.

The park incorporates the valleys of the Gwynns Falls and its tributaries, extending more than six miles (9.7 km) from the western municipal limits south to Wilkens Avenue.

An 1831 traveler expressed surprise at discovering the valley's "wild and beautiful scenery [...] so near the city, surrounded by all the various majestic features of a rocky mountainous country.

[6] Facilities in this section include the headquarters of the Chesapeake Bay Outward Bound School, with its outdoor activities programs, the Carrie Murray Nature Center.

[8] The Gwynns Falls Trail extends the length of Leakin Park from the terminus of Interstate 70 (I-70) to Wilkens Avenue, in the Winans Meadow section.

Constructed in stages from 1999 to 2008, the trail opened the stream valley to active recreational use for hikers and bikers,[9] with trailheads and provision for parking along the route.

Leakin Park traces its earliest history to a small tract near Edmondson and Hilton avenues, designated in 1901 as the Gwynns Falls Reserve.

In 1904, as the city anticipated expanding its borders through annexation, the highly regarded Olmsted Brothers firm proposed creating "stream valley parks" to protect distinctive watersheds like the Gwynns Falls from future development and secure them as natural preserves.

[26] In an editorial on the controversy, The Baltimore Sun insisted that "BGE must work with the city and other stakeholders to find the least damaging route for a new gas line through the area.