Binbrook's first multi? Maybe or maybe not, but at the time when it was placed, it was the only one (not counting the conservation area).
At the posted coordinates you will find a historical marker (a rock really) commemorating a former business which existed at this location.
There are two year numbers listed: ABCD - EFGH
The final is located at: N 43° 7.[D+H][D][G+A]' W 79° 49.[E][C][G+D]'
Trailhead at (and parking nearby): N 43° 7.[D+D][A+G][H+E]' W 79° 49.[A-E][C+D][C]'