This preserve features a 5-acre spring-fed marsh pond, unusual for its alkaline waters, which is a nesting site for ducks. A 13-acre dense hardwood forest dominated by black birch thrives nearby. Preserve can be accessed from the orange trail of the Marian Yarrow Preserve or from Todd Road. Stanley O. Grierson donated the Mildred E. Grierson Memorial Wildlife Sanctuary in 1973 in memory of his mother.
- I-684 to exit 6
- East on Rt. 35 to North Salem Rd.
- Left on North Salem Road for 0.25 miles to Mt. Holly Rd
- Turn right (east) onto Mount Holly Rd. for 1.5 miles to a sharp left.
- To reach the Mt. Holly Preserve, go straight here onto Mt. Holly Rd.
- East for approx. one mile.
- Preserve is on left side of road.
- continue on Mt. Holly Rd.,
- Turn right onto Todd Road.
- Preserve is 100 yards on right.
- For all preserves, park on roadside.