Hiking Trails and Parks in Warren County NJ to Explore

Beyond the Water Gap, Warren County, NJ is full of state forests, county preserves and reservoir trails that are quieter and closer to home. These are the parks worth knowing, with practical details for the colder months.

Jenny Jump State Forest

• Where: State Park Road area, Hope Township

Jenny Jump has seven official trails, most near the camping area at the north end of the forest. The Jenny Jump Trail is the longest at 8.4 miles across the ridgelines, while the 1.8 mile Ghost Lake Trail is rated easy and the 1.4 mile Summit Trail passes big boulder piles on the way to the ridge. The views over the Kittatinny Valley are some of the best in central Warren County.

NJ State Parks: Jenny Jump map and trails

Merrill Creek Reservoir

• Where: 34 Merrill Creek Road, Washington (Harmony Township)
• When: Gates open 7 a.m.; from October 1, 2026 to March 15, 2027 gates close at 4:30 p.m.

Merrill Creek’s trails circle a reservoir that is a designated Important Bird and Biodiversity Area and a winter roost for snow geese. Watercraft are not allowed on the reservoir from December 1 to March 15 to protect wintering birds, and the visitor center is open Wednesday to Sunday, 10 a.m. to 4 p.m. Note that the whole property closes to the public for deer management December 7 to 12 and December 18, 2026, and on Thanksgiving and Christmas Day.

Merrill Creek Reservoir

White Lake Natural Resource Area

• Where: 97 Stillwater Road, Hardwick Township
• When: Naturalist led Take a Hike Day hike: Tuesday, November 17, 2026, 10 a.m. to 1 p.m.

This 441 acre county preserve centers on White Lake, a deep, spring fed lake of about 69 acres. Warren County Park Naturalists lead a roughly four mile hike here for National Take a Hike Day, with options to shorten it. Dress for moderate climbs and descents.

Explore Warren: Take a Hike Day

Oxford Mountain Natural Resource Area

• Where: Academy Street, Oxford Township

A highlight of the Warren Highlands Trail, this 349 acre preserve climbs Oxford Mountain above the town of Oxford. County naturalists describe sections of steep incline and decline, so plan for a workout. Afterward, walk over to see the historic Oxford Furnace in town.

Explore Warren: Oxford Mountain NRA

Florence Kuipers Park

• Where: Grand Avenue parking lot, Hackettstown
• When: Birding for Beginners walk: Monday, November 9, 2026, 7:30 to 9:30 a.m.

The park preserves more than a mile of the old Morris Canal prism and towpath beside the state’s Rockport Wildlife Management Area. The mowed trail is mostly flat with one moderate hill at the start, which makes it a good pick for an easy walk or a first birding outing. Warren County Parks lends a limited number of binoculars on the guided walk.

Explore Warren: Birding for Beginners

Cold Weather Trail Tips

• Winter daylight is short, and some properties lock their gates in the afternoon, so plan your return time.
• Fall and winter are hunting seasons in New Jersey; wear bright colors and check each property’s closure dates.
• Pack traction for icy rock on ridge trails like Jenny Jump.
• Bring a printed map, since cell service can be spotty in the hills.

Which Park Fits Your Day

• Short and flat: Florence Kuipers Park in Hackettstown, for a canal towpath stroll.
• Big ridge views: Jenny Jump State Forest in Hope, especially the Summit Trail.
• Wildlife watching: Merrill Creek Reservoir, where snow geese gather in winter.
• A guided outing: White Lake with Warren County Park Naturalists on November 17.

Warren County Parks also posts free naturalist programs through the year on the county tourism calendar, and many are family friendly. Signing up ahead is the best way to secure a spot, since group sizes are often limited.

More in Warren County: for the big views, see our guide to the Delaware Water Gap on the New Jersey side.