Gartcarron Bridge is the first road bridge to cross the Endrick Water after it source in the hills near the Carron Valley Reservoir. It is therefore a very small bridge, crossing a very small river! The bridge is a single stone arch of uncertain date. The only decoration is the ashlar stone used for the arch ring. The rest of the bridge is built of rubble stone, except for the abutment courses below the arch, which use a style of stone only briefly fashionable in the Victorian era, suggesting that the bridge is somewhat later than first impressions may suggest.
The road way rises either side before reaching the bridge, giving the impression of a hump-backed bridge. The bridge is also narrower than the road on either side, and with the bends on either bank this produces a significant pinch point, especially for traffic approaching from the fast flowing section along the reservoir.