Every fall, tens of thousands of hawks, eagles, and falcons follow a single Pennsylvania ridge southwest toward the Gulf of Mexico and South America. Before 1934, people stood on that ridge and shot them for sport. Today people stand on the same rocks with binoculars and a clicker, and they have been counting ever since.
That ridge is the Kittatinny Ridge, also called Blue Mountain, and it runs 185 miles across 11 Pennsylvania counties. The Pennsylvania Game Commission calls it the state's largest Important Bird Area. It is a long, unbroken wall of forest oriented northeast to southwest, which happens to be the exact direction a hawk from New England or eastern Canada wants to go in September.
eBird lists 298 species for Lehigh County and 281 for Schuylkill County, and three places along a 30-mile stretch of the ridge account for a lot of that: Hawk Mountain Sanctuary, the most famous hawk watch in the world; Bake Oven Knob, the free, quieter lookout on the Appalachian Trail; and the Lehigh Gap Nature Center, a former zinc smelter wasteland that grew back into a warbler refuge.
Why the Kittatinny Ridge Is the Best Place in the East to Watch Hawks
Hawks are lazy in the best way. A migrating raptor wants to cover distance without flapping, and there are two ways to do that: circle up inside a thermal of rising warm air, or ride the updraft that forms when wind hits a ridge and deflects upward. The Kittatinny Ridge offers both.
On a northwest wind, the whole ridge becomes a conveyor belt. The air hits the north face, rises, and hawks slide along the crest at eye level or below it, sometimes close enough that you can see the eye of a passing Sharp-shinned Hawk without binoculars. On calm, sunny days the Broad-winged Hawks do the other thing: they stack into kettles of dozens or hundreds, spiral up a thermal, and peel off the top in a long glide to the next one.
The history is the other reason this ridge matters. In the early 1930s, gunners gathered on Hawk Mountain every autumn and shot hawks by the thousands, for sport and on the theory that they were pests. In 1934 the conservationist Rosalie Edge leased 1,400 acres of the mountain, hired Maurice and Irma Broun as wardens to keep the gunners off, and started a count. The Hawk Mountain count has run every autumn since, making it the longest-running raptor migration count in the world, and the sanctuary now covers about 2,600 acres. It was designated a National Natural Landmark in 1965.
Those 90-plus years of data are why we know what we know about raptor populations in eastern North America. Bald Eagles are the headline: Hawk Mountain's long-term autumn average is 146, the 10-year average is 537, and 2023 set an all-time record of 619. Red-tailed Hawks have gone the other way, from a long-term average of 3,015 to a 10-year average of 1,394.
When to Go: Kittatinny Ridge Birding by Season
🌸 Spring (Apr–Jun)
A smaller hawk flight: Hawk Mountain's spring count averages 972 raptors, led by Broad-winged Hawks. The real spring story is breeding warblers on the ridge. Bake Oven Road holds Cerulean, Worm-eating, and Hooded Warblers, and Prairie Warblers sing from the regrowing slopes at Lehigh Gap by May.
☀️ Summer (Jul–Aug)
The ridge is quiet and green, with Scarlet Tanager, Wood Thrush, and Pileated Woodpecker in the forest and Indigo Bunting and Blue Grosbeak on the open Lehigh Gap slopes. The Hawk Mountain count starts August 15, and the first Ospreys, Bald Eagles, and American Kestrels trickle through in the last two weeks of the month.
🍂 Fall (Sep–Nov)
The main event. Broad-winged Hawks peak in mid to late September, when single days can top a few thousand birds. Sharp-shinned Hawks and Ospreys build through early October, and late October brings the best variety of the season, with Red-tailed Hawks, Red-shouldered Hawks, and the first Golden Eagles. Warbler migration overlaps the hawk flight all through September.
❄️ Winter (Dec–Mar)
Golden Eagles and late Red-tailed Hawks keep moving into early December, and the Hawk Mountain count ends December 15. After that the ridge is for winter finches and resident birds. Hawk Mountain closes some trails during deer season from late November through January, trails are not winter maintained, and Bake Oven Road can be icy.
Trail 1: Lookout Trail to North Lookout at Hawk Mountain Sanctuary
The world's longest-running raptor migration count happens on these rocks. North Lookout has a 200-degree view that reaches 70 miles on a clear day, 216 species on eBird, and in September a flight of Broad-winged Hawks that can run into the thousands.
This is the one to do first, and if you only have one morning, it is the only one you need.
The Lookout Trail climbs about a mile from the visitor center to North Lookout at 1,521 feet, where the official count happens every day from August 15 to December 15. The first stop, South Lookout, is only 175 yards from the trailhead on a groomed path that is wheelchair accessible, and it looks straight down onto the River of Rocks, an Ice Age boulder field in the valley below. An observer-interpreter is stationed at South Lookout daily from September to early November, which makes it the best place to learn to tell a Sharp-shinned Hawk from a Cooper's Hawk at 300 yards. After that the trail gets rocky, rises about 300 feet, and ends on a jumble of sandstone boulders with a 200-degree view that extends 70 miles.
The eBird numbers are the best in the region. The North Lookout hotspot (L1299466) has 216 species across 5,212 checklists, the most of any hotspot in Schuylkill County, and 173 species on its September list alone. That list includes 14 diurnal raptor species and 33 warbler species, which is not a typo. The warblers move along the ridge at the same time as the hawks, and a lot of people are standing on that lookout with binoculars in September.
A juvenile Sharp-shinned Hawk. First-year birds like this one make up a large share of the Sharp-shinned flight past North Lookout, which peaks in mid October. Photo: Sandra Uecker / Public Domain, via USFWS
What to expect in mid to late September: Broad-winged Hawk above everything else. The long-term autumn average is 8,076 birds, and nearly all of them pass in a window of about two weeks. The record day was September 14, 1978, when 21,496 raptors passed North Lookout, 21,448 of them Broad-wings. In a normal year, the best day of the season lands somewhere in the second half of September. As of September 16, 2026, the count stood at 7,163 raptors for the season, including 5,824 Broad-winged Hawks, with a best day of 1,558 on September 12.
Alongside them: Bald Eagle (218 already this season), Osprey, Sharp-shinned Hawk, American Kestrel, Merlin, and Peregrine Falcon. The September eBird list also has the rarities that a lot of eyes produce: Mississippi Kite, Golden Eagle, American Goshawk, and, somehow, Sabine's Gull and Anhinga flying over a mountaintop in Pennsylvania.
The warbler list is the underrated part. Cape May, Bay-breasted, Blackpoll, Black-throated Blue, Connecticut, Mourning, and Golden-winged are all on the September list. They feed in the oaks and birches right at eye level from the lookout, and during a slow hawk hour they are the show.
If you want more mileage: the sanctuary's other trails are hard. The River of Rocks Trail drops 600 feet into the boulder field and takes three to four hours as a loop; the sanctuary rates it very difficult. The Skyline Trail involves four-point rock scrambling and a 30-foot vertical descent. The combination AllTrails calls the Hawk Mountain Loop is 5.4 miles and rated hard, with 4.8/5 across 3,875 reviews. None of it is necessary for the birds: the hawks come to the lookout.
Practical notes: Hawk Mountain Sanctuary is at 1700 Hawk Mountain Road, Kempton, PA 19529, phone 610-756-6961. Trail admission is $10 for adults, $7 for seniors 65 and up, $5 for children 6 to 12, free for children 5 and under and for members; buy at the visitor center or online. Posted hours are 9am to 5pm daily. No pets anywhere on the sanctuary. Fall weekends with a northwest wind are busy, and North Lookout gets crowded by late morning, so arrive when the gate opens. Bring a cushion: the lookout is all rock, and you will be sitting on it for hours.
Best months: Mid to late September for Broad-winged Hawks; mid October to early November for variety and Golden Eagles
Trail 2: Bake Oven Knob via the Appalachian Trail
A free, half-mile hike to one of the oldest hawk watches in the country. The count has run every fall since 1961 and has passed 800,000 raptors. Two lookouts, 178 species on eBird, and a fraction of the Hawk Mountain crowd.
Bake Oven Knob is what you do when Hawk Mountain is packed, or when you want to watch the same flight without the admission fee and the crowd. It sits on the same ridge about 15 miles northeast, and the birds do not know the difference.
The local ornithologist Donald S. Heintzelman started an autumn hawk count here in 1961. It has run every fall since, now under the Lehigh Gap Nature Center, and more than 800,000 migrating raptors have been tallied in that time. Nineteen raptor species have been recorded. The Pennsylvania Game Commission puts the average at about 194 Bald Eagles a year, and the count also tracks migrating monarch butterflies.
A soaring Golden Eagle. The Kittatinny Ridge carries one of the largest Golden Eagle flights in the East, mostly from late October into December, on the kind of hard northwest wind that keeps everyone else home. Photo: James "Newt" Perdue / Public Domain, via USFWS
The hike is short and rough. From the parking lot at the top of Bake Oven Road, follow the white-blazed Appalachian Trail uphill for 0.4 miles through rocky mixed hardwood forest to the old concrete foundation of a beacon tower. That is the South Lookout. The North Lookout is another 0.1 miles, downhill over large boulders. AllTrails lists the round trip at 0.8 miles with 4.7/5 across 967 reviews, and the reviews agree that it is short but not a walk in sneakers.
The Bake Oven Knob hotspot (L110) has 178 species across 891 checklists, third in Lehigh County, and 131 species on its September list. That includes 13 raptor species (Osprey, both eagles, Northern Harrier, Sharp-shinned and Cooper's Hawks, American Goshawk, three buteos, and three falcons) and 25 warbler species. The warbler list has Cerulean, Connecticut, and Orange-crowned, plus a Townsend's Warbler, a western bird that has no business in Lehigh County and turned up anyway. Common Nighthawk flocks drift over the ridge in the evenings in early September, and Ruffed Grouse is on the list too.
Drive the road slowly. The Pennsylvania Society for Ornithology site guide recommends walking downhill from the third switchback on Bake Oven Road, where several pairs of Cerulean and Worm-eating Warblers and one or two Hooded Warblers breed. In September those birds are leaving, but the road is still one of the best places on the ridge to see Wild Turkey and Pileated Woodpecker without trying.
Practical notes: The lookouts are reached from the parking lot on Bake Oven Road at the ridge crest, near Germansville. Bake Oven Road is steep and partly unpaved near the top. No fee, no facilities, no water. The volunteer counters are there from August through November; be friendly and ask what is flying, since they will almost always point out birds for you. This is state game land, so wear blaze orange during hunting seasons.
Best months: Mid to late September for Broad-winged Hawks; late October and November for Golden Eagles; May and June for breeding Cerulean Warblers on the road below
Trail 3: Prairie Warbler, Appalachian, and Charcoal Trail Loop at the Lehigh Gap Nature Center
A mountainside a zinc smelter killed, replanted with native grasses, and now alive with Prairie Warblers, Blue Grosbeaks, and hawks moving along the ridge above. The loop climbs from the Osprey House onto the restored slope and back down through woodland.
This is the one with the best story. For 80 years, until 1980, the New Jersey Zinc Company ran smelters in Palmerton, at the base of the ridge, and the metal fallout killed the soil and nearly everything growing on the mountainside above them. The area was designated part of a 3,000-acre Superfund site in 1983.
In 2003 the Lehigh Gap Nature Center acquired 756 acres of the damaged ridge and started planting native warm-season grasses. Those grasses have roots that go 12 to 14 feet deep and build soil as they grow, and they took. The slope is now a mix of prairie grassland, young woodland, and rock, and the nature center describes it as the only Superfund site in the country turned into a nature center. It is also home to Pennsylvania's largest native population of wild bleeding heart, which is not a sentence I expected to write about a Superfund site.
Prairie Warbler, which despite the name wants young scrub and regrowing clearings, not prairie. The restored slopes at Lehigh Gap suit it so well that one of the trails is named after it. Photo: Susan Young / Public Domain, via USFWS
The loop starts at the Osprey House, the nature center's visitor building on Paint Mill Road. Take the Prairie Warbler Trail southwest to the Woodpecker Trail, climb the white-blazed Appalachian Trail onto the open slope, and come back clockwise on the Charcoal Trail, Prairie Grass Trail, and LNE Trail. AllTrails puts it at 3.6 miles, moderate, with 4.6/5 across 586 reviews. The AT section is steep and rocky; the reward is a wide-open view of the Lehigh River cutting through the ridge, with hawks passing at eye level on a good day.
If climbing is not the plan, the refuge's flat trails work too. The D&L Trail runs 2.75 miles along the Lehigh River and is the only trail link between the 165-mile Delaware and Lehigh Trail and the Appalachian Trail. The Three Ponds Trail and Bobolink Trail are short and easy.
The Lehigh Gap Nature Center hotspot (L372158) at the Osprey House has 149 species across 327 checklists, and the Carbon County side of the refuge (L889203) has another 157 across 292. Between the two September lists there are 19 warbler species, including Cape May, Bay-breasted, Canada, and Worm-eating, plus Osprey, Bald Eagle, Northern Harrier, Merlin, and Peregrine Falcon. The open-country birds are what make this site different from the forested lookouts: Blue Grosbeak, Indigo Bunting, Field Sparrow, Eastern Bluebird, and Red-headed Woodpecker, all on the September lists.
Practical notes: Lehigh Gap Nature Center is at 8844 Paint Mill Road, Slatington, PA 18080, phone (610) 760-8889. The refuge is open daily sunrise to sunset and free. Restrooms are at the Osprey House. Leashed dogs are allowed. Bikes are allowed on the D&L Trail and the flat section of the LNE Trail only. Black bears are common on the ridge, so make some noise on the upper trails.
Best months: September for migrant warblers and hawks; May and June for breeding Prairie Warbler and Blue Grosbeak
Signature Species of the Kittatinny Ridge
🦜 Birds Worth Planning Around
Planning Your Trip
Getting there: Lehigh Valley International Airport (ABE) in Allentown is the closest airport to all three sites. Hawk Mountain is roughly two hours from Philadelphia and about two and a half from New York City, which makes it a realistic day trip from either. Bake Oven Knob and Lehigh Gap are closer to Allentown, and the three sites sit within about 30 miles of each other along the ridge.
A realistic two-day plan: Check the forecast first and let the wind decide. On the first day after a cold front, with northwest wind, go straight to North Lookout at Hawk Mountain and plan to stay until mid afternoon; this is the day you came for. On a calmer day, walk the Lehigh Gap loop early for warblers and open-country birds, then drive up to Bake Oven Knob for the late morning and early afternoon, when the thermals get going and the Broad-winged kettles form. If you only get one fall weekend, aim for the third or fourth weekend in September.
Weather and timing: Hawk Mountain's own advice is that the best flights come one to two days after a cold front, on northwest winds. Most migrating hawks pass between 8am and 5pm, with mid to late morning and mid afternoon usually strongest on calm days. On strong winds, birds can move from dawn to dusk. South winds and rain mean a slow day, and those are the mornings to bird the woods for warblers instead.
What to bring: Binoculars first; a scope is optional, since most hawks are identified on shape and flight style, not detail. A seat cushion for the rocks, a warm layer even in September (lookouts are windy and you are not moving), and sturdy shoes for the Lookout Trail and the Appalachian Trail. Sunscreen and a hat: there is no shade on the lookouts.
eBird resources: Schuylkill County (US-PA-107), Lehigh County (US-PA-077), and Berks County (US-PA-011) cover the three sites. Targeted hotspots: Hawk Mountain Sanctuary North Lookout (L1299466), Hawk Mountain Sanctuary South Lookout (L1585781) at 171 species, Bake Oven Knob (L110), Lehigh Gap Nature Center, Lehigh County (L372158), and Lehigh Gap Nature Center, Carbon County (L889203). Hawk Mountain posts its daily count online, which is the best way to see whether the flight is on before you drive.
Other guides: For the coastal version of fall raptor migration, where a peninsula funnels hawks instead of a ridge, see the Cape May birding guide. For the southern end of the same Appalachian chain, see the Great Smoky Mountains guide. For another place to watch Broad-winged Hawk kettles in September, see the Missouri Ozarks guide.
How to watch a hawk flight: Do not stare at the horizon hoping something appears. Pick a landmark on the ridge to the northeast (the counters at Hawk Mountain use numbered landmarks along the ridge, and they will tell you which is which) and scan slowly back and forth just above it. Broad-winged kettles show up as a loose swirl of specks that tighten as they climb. Once you find one, keep watching it: the birds stream off the top one at a time in a long glide, and a single kettle can mean a hundred birds in five minutes. And when a counter calls out a bird, look where they are pointing, not at them.
FAQ: Hawk Mountain and Kittatinny Ridge Birding
When is the best time to see hawks at Hawk Mountain?
The official count runs August 15 to December 15. Mid to late September is Broad-winged Hawk season and produces the biggest single-day totals, often several thousand birds on a good day. Late October has the best variety, with Sharp-shinned Hawks, Red-tailed Hawks, and the first Golden Eagles. The best flights come one to two days after a cold front passes, on northwest winds.
How much does it cost to visit Hawk Mountain Sanctuary?
Trail admission is $10 for adults, $7 for seniors 65 and over, $5 for children 6 to 12, and free for children 5 and under and for members. Posted hours are 9am to 5pm daily. Pets are not allowed anywhere on the sanctuary.
How long is the hike to North Lookout at Hawk Mountain?
About a mile each way on the Lookout Trail, with roughly 300 feet of climbing over rocky, ungraded footing. AllTrails lists the round trip at 1.9 miles. South Lookout is only 175 yards from the trailhead on a groomed, wheelchair-accessible path, and it has a daily interpreter from September to early November.
How many raptors migrate past Hawk Mountain each fall?
Hawk Mountain puts its autumn average at about 18,000 raptors. The long-term average for Broad-winged Hawk alone is 8,076. The record day was September 14, 1978, when 21,496 raptors passed North Lookout, 21,448 of them Broad-winged Hawks. Bald Eagles have climbed sharply: the 10-year average is 537 against a long-term average of 146.
Is Bake Oven Knob a good alternative to Hawk Mountain?
Yes. Bake Oven Knob is about 15 miles northeast on the same ridge, has been counted every fall since 1961, and has no entrance fee. The South Lookout is 0.4 miles up the Appalachian Trail from the parking area on Bake Oven Road. It gets the same kind of flights with far fewer people, and eBird lists 178 species there.
What is the Lehigh Gap Nature Center?
A 756-acre wildlife refuge on the Kittatinny Ridge at Lehigh Gap, on land that a zinc smelter left almost bare during 80 years of operation. The site became part of a Superfund area in 1983, and the nature center acquired it in 2003 and replanted it with native warm-season grasses. It now has more than 13 miles of trails, open sunrise to sunset and free, and 149 species on eBird at the Osprey House trailhead.
What weather is best for hawk watching in Pennsylvania?
Northwest winds one to two days after a cold front. The wind strikes the ridge and deflects upward, and hawks ride that updraft along the ridgeline for miles without flapping. On calm, sunny days they use thermals instead, which puts them higher and later, typically mid to late morning and early afternoon. South winds and rain usually mean a slow day.
Photo Credits
- Hero image: Bald Eagle in flight. Photo by Emily Hodapp/USFWS. Public Domain.
- Inline image 1: Juvenile Sharp-shinned Hawk. Photo by Sandra Uecker/USFWS. Public Domain.
- Inline image 2: Soaring Golden Eagle. Photo by James "Newt" Perdue/USFWS. Public Domain.
- Inline image 3: Prairie Warbler. Photo by Susan Young/USFWS. Public Domain.