[3] SH 257 then heads northwards before turning northwest,[4] crossing over the Cache la Poudre River and entering Windsor.

It abruptly turns west and begins a concurrency with intersects Colorado State Highway 392 (SH 392) along Main Street.

The route went north to Windsor from Milliken, then turning west to Colorado State Highway 185 (SH 185).

[5] In November 2009, a new traffic signal was installed at the intersection with Garden Drive in Windsor.

State Highway 257 Spur (SH 257 Spur) was a 1.1-mile (1.8 km) state highway business route in Weld County.