Round Valley Reservoir, New Jersey, USA

Welcome to the ultimate guide to Round Valley Reservoir — things to do, where to stay, fun facts, history, stats and more. Let’s dive in!

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All About Round Valley Reservoir

Round Valley Reservoir spans 2,350 acres in Hunterdon County, New Jersey. The reservoir fills the valley formed by the ring-shaped Cushetunk Mountain, which was once an active volcano. Named for the circular shape of the valley in which it sits, the reservoir is known for the exceptional clarity of its waters and its thriving fish population. With a maximum depth of 180 feet, it also New Jersey’s deepest lake.

Round Valley Reservoir was created in the 1960s by the New Jersey Water Authority. Because of the valley’s natural concave shape, just two dams and a dike were needed to enclose it completely, and the reservoir was flooded with 55 billion gallons of water. Today, Round Valley is a crucial part of the water supply system for central New Jersey, as well as a favorite recreation area.

Round Valley Reservoir offers some of the best fishing in the state. Nineteen species of fish inhabit Round Valley Reservoir, and on a warm summer day you will find anglers hoping to make a record catch. The reservoir is stocked yearly with rainbow trout and brown trout, and state records have been set at Round Valley for lake trout and brown trout, as well as freshwater eel and smallmouth bass. Also found in the lake are largemouth bass, pickerel, catfish, and yellow perch. Anglers can fly-fish for trout from the shore, or fish by boat. To preserve the purity of the reservoir’s waters, motorboats are restricted to engines of no more than 10 horsepower. Also welcome at the lake are canoes, kayaks, and sailboats.

Round Valley Reservoir’s clear blue water makes it ideal for scuba diving, skin diving, and snorkeling. The lake’s exceptional visiblity makes it easy for divers to study a wide variety of fish and plant life. With a maximum depth of 180 feet, there is plenty of room to explore. Round Valley also has a designated swimming area separate from the main reservoir. The public swimming beach is open from Memorial Day to Labor Day and has all the amenities necessary for some fun in the sun: restrooms, showers, concession stands, and even playgrounds and volleyball nets.

Nature lovers won’t be disappointed with a visit to Round Valley. The lake is surrounded by over 5,000 acres of woodlands, and birdwatchers can spot hawks, ospreys, loons, and herons hunting the lake’s waters. There have also been sightings of bald eagles nesting on nearby Cushetunk Mountain. Round Valley Recreation Area offers hiking opportunities for all skill levels, from the rugged nine mile Cushetunk Trail for skilled hikers, mountain bikers, and horseback riders, to the one mile Pine Tree Trail, best suited to birdwatchers and families. Nearby Cushetunk Mountain Nature Preserve offers more opportunities for hiking and mountain biking and some difficult mountain trail. In the winter months, visitors trade their hiking boots for ski boots, as Round Valley is transformed into a winter wonderland for skiing and sledding.

If camping is your passion, then Round Valley is the place for you. It is one of the few parks in the state to offer wilderness camping, with 85 tent sites that are accessible only by a three mile hike or by boat. These sites are equipped with fire pits, and water pumps and outhouses are available along the hiking trail. If these accommodations sound a little too basic, don’t worry: there are hotels and even a few bed and breakfasts just a short drive away.

Fishing, diving, camping, hiking–with such a wide variety of activities for all ages, the reason for Round Valley’s popularity is as clear as its waters. No matter what the season, Round Valley Reservoir is the perfect place to get away from it all.

Things to Do at Round Valley Reservoir

  • Fishing
  • Boating
  • Sailing
  • Swimming
  • Beach
  • Canoeing
  • Kayaking
  • Snorkeling
  • Scuba Diving
  • Camping
  • Hiking
  • Biking
  • Horseback Riding
  • Hunting
  • Birding
  • Playground

Fish Species Found at Round Valley Reservoir

  • Bass
  • Black Bass
  • Brown Trout
  • Catfish
  • Eel
  • Lake Trout
  • Largemouth Bass
  • Perch
  • Pickerel
  • Pike
  • Rainbow Trout
  • Smallmouth Bass
  • Trout
  • Yellow Perch

Find Places to Stay at Round Valley Reservoir

If you’re considering a Round Valley Reservoir lake house rental or hotel, we’ve made it super easy to find the best rates and compare vacation accommodations at a glance. Save time using this interactive map below.

Recommended Sites to Book a Round Valley Reservoir Vacation

If you want to take a deeper dive to find waterfront lake cabins, cottages, condos, hotels or resorts, check out our favorite Round Valley Reservoir lodging partners.

  • VRBO – Use VRBO to find the perfect lake rental home, condo, cabin, cottage or other vacation property.
  • – One of the world’s leading digital travel companies, connects travelers to everything from cozy B&Bs to luxury resorts.
  • Expedia – Expedia is a popular online travel agency with more than 140,000 lodging properties worldwide.
  • – With more than 325,000 hotels in 19,000-plus locations, is an industry leader in online accommodations.
  • TripAdvisor – Read traveler reviews and compare prices on hotels, vacation rentals and more at TripAdvisor.
  • Trivago – Trivago helps travelers compare deals for hotels and other accommodations from a variety of booking sites.
  • KAYAK – KAYAK scours hundreds of other travel websites at once to find the best deals on hotels and other travel-related services.
  • RVshare –RVshare connects travelers interested in renting a motorhome with owners who have RVs to rent.
  • CampSpot – Campspot offers premier RV resorts, family campgrounds, cabins and glamping options across North America.

Note: These are affiliate links so we may earn a small commission if you book through them. While there is no extra cost to you, it helps provide resources to keep our site running (thank you)! You can read our full disclosure policy here.

Round Valley Reservoir Statistics & Helpful Links


Lake Type: Artificial Reservoir, Dammed

Water Level Control: New Jersey Water Supply Authority

Surface Area: 2,350 acres

Shoreline Length: 12 miles

Normal Elevation (Full Pond): 381 feet

Minimum Elevation (Min Pond): 385 feet

Maximum Elevation (Max Pond): 361 feet

Average Depth: 60 feet

Maximum Depth: 180 feet

Water Volume: 168,788 acre-feet

Completion Year: 1965

Drainage Area: 5 sq. miles

Trophic State: Ogliotrophic

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