It then bears left onto Fourth Avenue South, which curves into 15th Street East, where it runs in its intended south-to-north direction for the first time.

North of Steinhatchee SR 51 is named St. Linhatchee Drive[citation needed] and winds through the wetlands of southeastern Taylor County.

One other county road terminates at SR 51 in the town, specifically CR 355 which continues west as Pine Street.

This trajectory end at 11th Street where CR 136 officially joins SR 51 in an overlap, however both are overshadowed by US 129 (South Ohio Avenue).

Further downtown it becomes the location for the Old Live Oak Post Office, and later, the Suwannee County Courthouse, and then the four corners of the city at U.S. Route 90 (hidden SR 10), where US 129/SR 51's name changes from South Ohio Avenue to North Ohio Avenue, and US 90's name changes from West Howard Street to East Howard Street.

Unlike in Suwannee County, only a hint of the right-of-way of the former segment of US 129 can be found before the road turns straight north before letting go of its multiplex with CR 132, which runs east.

Further north it enters the unincorporated community of Marion, where it intersects one other county road before meeting another interchange, this time Interstate 75 at Exit 451 Beyond that, it passes through Hillcoat, where US 129/SR 51 joins US 41 as well as hidden SRs 25 and 100.

The road winds through local Northern Florida forest land with occasional wetlands even as it passes through the barely existing community of Bakers Mill.

After crossing a narrow bridge over the Little Alapaha River it intersects a dirt road named Northwest 13th Street which leads to US 129 near Avoca.