At the intersection of Power Vista Drive and Monteagle Trail (right by the NYPA Niagara Power Vista and the edge of Niagara University's campus), you are standing directly at the crest of the Niagara Escarpment, overlooking the Niagara Gorge.

Because of the dramatic relief and the way the Robert Moses Power Plant was excavated into the cliffside, the exact "rock type" depends on whether you are looking at the surface bedrock where the roads sit, or the massive vertical section exposed right next to them.

1. The Surface Bedrock: Lockport Group

If you are standing on the pavement or the grass at that specific intersection, the underlying surface bedrock is Dolostone (specifically the Lockport Group).

Wikipedia

• Rock Type: Sedimentary (Magnesian Limestone / Dolostone)
  The New York State Museum - nysed

• Age: Middle Silurian (around 425–430 million years old)
  The New York State Museum - nysed

• Characteristics: It is a hard, highly resistant, brownish-gray rock. Because it resists weathering far better than the softer rocks beneath it, it acts as the classic caprock that forms the very top edge of the escarpment and the gorge walls right there.
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2. The Gorge Wall Exposure (The Vertical Section)

If you step onto the observation decks or look down the gorge walls immediately adjacent to Power Vista Drive, you are looking at a textbook stratigraphic column of Western New York. The excavation for the power project sliced completely through the Silurian and upper Ordovician layers.

As you look from the top down toward the river level, the rocks transition through three major types:

Formation / Group

Dominant Rock Type

Field Notes

Lockport Group

Dolostone

The tough caprock right under your feet.

Rochester Formation

Shale

A thick, bluish-gray, highly fossiliferous mudrock directly beneath the Lockport. It's soft and easily weathered.

Clinton & Medina Groups

Alternating Limestones, Shales, and Sandstones

Includes units like the dense Irondequoit Limestone, the thin Neagha Shale, and the prominent, pale Whirlpool Sandstone further down.

Queenston Formation

Shale

The brilliant red shale visible near the base of the gorge/power plant, dating back to the Late Ordovician.

So, if you are looking for a quick answer for the ground right beneath that intersection, it's Lockport Dolostone. If you are looking at the cliff face it sits on, it's a massive, vertical sandwich of dolostone, shale, and sandstone.

Wikipedia