SR 21BU follows the original alignment of SR 21 through the city of Sylvania. Measuring 2.87 miles in length, SR 21BU follows a combination of S Main Street, Ogeechee Street alongside U.S. 301BU/SR 73 and Mims Road. SR 21 bypasses the Screven County seat along Perimeter Road and U.S. 301/SR 73LO, both four lane, divided highways.

South
The first confirming marker for SR 21BU stands south of U.S. 301/SR 21-73LO.
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A distance sign alludes to when SR 21BU along Mims Road was still part of SR 21.
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The Screven County Courthouse lies SR 21BU (Mims Road) south of Rocky Ford Road.
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SR 21BU (Mims Road) continues south to U.S. 301BU/SR 73 at Ogeechee Street.
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U.S. 301BU is incorrectly marked as part of the U.S. 301 mainline.
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SR 21BU combines with U.S. 301BU/SR 73 (Ogeechee Street) east 0.49 miles to S Main Street in Downtown Sylvania.
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Page Updated Thursday March 17, 2022.