The portal lies just west of the old tramway and is constructed from stone, remaining intact for the first 15 yards. Inside, remnants of a ventilation furnace firebox can still be seen on the right, while the chimney that once served it stood until the 1950s. The adit proceeds on a heading of 294° magnetic (as surveyed in April 1997), with intermittent stone pillars on the left side supporting the roof.

Roughly 50 yards in, flowing water can be seen running outbye before dropping down a sloped heading on the right, which continues for another 200 yards before becoming too tight to follow. This water is believed to enter the Miles Water Level system, hundreds of feet below. Continuing straight, the level splits, with several short side passages branching off. In these areas, water ranges from 6 to 12 inches deep but shallows as one moves further in.

The main route narrows and the roof drops to around four feet high, where cast iron plate rails can still be seen in place. The passage gently curves, with old branches diverging occasionally to the right. Coal extraction left voids on either side of the level, which were then packed with deads (waste rock) for support. After 150 yards, a collapse marks the point where iron roof supports have failed. Scuff marks from old mine trucks can still be observed in the clay along the route.

A branch to the left toward the end of the adit leads to deeper, ochre-stained water backed up due to blockage. Rotting timber props remain visible in this section, but a narrowing air space forced the termination of further exploration.

To the left of the main entrance, a more recent timber-lined drift mine quickly becomes flooded with very limited headroom. Nearby are two shafts and traces of other modern entrances that once gave access to workings connected with the Bixslade Low Level. As of the last inspection, the Bixslade High Level entrance has been fenced off.

Driven in 1826 by David Mushet, a key figure in ironmaking innovation, who conducted extensive smelting experiments at his Coleford works. This adit was engineered to drain the elevated ground west of Cannop Valley and access the highly productive Coleford High Delf coal seam, which reached up to seven feet in thickness. By 1841, the workings had yielded 21,000 tons of coal, making it the third largest producer in the Forest that year.