It connects to several of the region's major east–west roads, including U.S. Route 20 (US 20) and the New York State Thruway (Interstate 90 or I-90).

Over the next 30 years, NY 77 was truncated and extended several times, moving the south end of the route to various locations in Wyoming and Genesee counties.

[3] North of Bennington hamlet, the highway traverses some swampy areas on its way into Genesee County, where it crosses the Norfolk Southern Railway's Southern Tier Line at a grade crossing just south of the Darien hamlet of Darien Center.

In the small community, located southeast of Darien Lakes State Park, NY 77 intersects the cross-state US 20.

The road, however, remains a two-lane highway as it continues north to the town of Pembroke and the village of Corfu, where it intersects NY 33.

[3] Just beyond that junction, the truck stops and toll plaza associated with exit 48A of the New York State Thruway (I-90) come into view as the road dips slightly in elevation.

Past the Thruway, it once again continues in a more northerly fashion to the hamlet of Indian Falls, a community located on the northern bank of the Tonawanda Creek.

As it heads into Niagara County, NY 77 continues to trend slightly northward, running along the northern fringe of the Tonawanda Wildlife Management Area.

About 6 miles (10 km) northwest of the county line is the hamlet of McNalls,[3] which served as the southern terminus of the 1930s incarnation of NY 359.