There Evans points out the line where the exposed cross-section of the beam meets a flow of sand that was washed down the valley toward the ocean and blocked by this “intrusion.” The sand piled up in “rubbly,” pebbled horizontal layers still visible today as sandstone against the trap rock’s mass.Įvans picks up a couple of pieces of trap rock and breaks them open, then fishes two tiny magnifiers from his pocket so we can see the difference between the stone at the outside edge of the beam-magma that cooled quickly-and stone from the inside of the beam-magma that cooled more slowly and therefore had time to form tiny interlocking crystals. We cross Whitney at the intersection with Armory Street and walk uphill about 100 feet to a rocky outcrop I’ve driven past thousands of times without noticing a thing. This area was later blasted open to build Whitney Avenue, but evidence of the beam remains on the west side of the road. We park in the lot at the Eli Whitney Museum, where Whitney once built his arms factory at a natural waterfall that cascaded over the beam connecting the two ridges. The central piece that once more clearly linked the two ridges can still be spotted in several places across New Haven, most notably at Evans’s favorite geological outcrop in the city, where we head together to take a look. Picture East Rock and West Rock as the top and bottom of an I beam lying on its side, Evans suggests.

Though the two rocky ridges that bookend our city appear distinct, they’re actually connected. The rock we see today rising up as the East and West Rock ridges was once underground magma that cooled and solidified and later rose to the surface. The geological story of how East and West Rock came to be takes us back 200 million years, Yale geology professor David Evans says, to a time when active volcanoes were spewing fountains of lava from fissures in the earth. For novice birdwatchers, there's a short nature trail along the Mill River with interpretive signs depicting local fauna.W hat New Havener hasn’t been stunned on a sunny evening by the view of West Rock’s cliffs bathing Westville in their carmine light, or by East Rock’s sheer rosy face, frilled with trees, basking in the glow of the sinking sun? Holding the city as if between two fingertips, these ridges of trap rock may be our finest natural landmarks. A keen eye might spot a beaver improving its dam in the Mill River, and flocks of wild turkeys are on regular patrol. The park plays host to a remarkable variety of wildlife. Its nearest visible neighbor along the same formation is West Rock, visible from the summit and points along the way.

Residents of the neighborhood to which it lends its name can be seen jogging, biking, and hiking its trails all four seasons of the year, and its ample picnic areas at base and summit are a magnetic draw throughout the warmer months.Įast Rock is a traprock ridge belonging to the Metacomet Ridge. western face and the white granite Civil War monument that rises from it, the eponymous rock is by far the most conspicuous landmark in the park, which also encompasses the humbler summits of Indian Head and Snake Rock. Downtown New Haven and the Long Island Sound seen from the summitįor city dwellers who can’t make it to the mountains, East Rock Park brings a mountain to the city.

New haven east rock park