If you carefully keep your bird records by county, be sure to use the specific hotspots in this park so that the birds will be assigned to the proper county. The Worcester-Middlesex county line runs north-south through the middle of Delaney Pond. Birds seen on the west side of the pond are in Worcester County. Birds seen on the east side of the pond are in Middlesex County.

This site is critical for an array of marsh birds and is a good site for spring migratory waterfowl as well. It represents one of the few areas of cattail marsh (away from Great Meadows) in the area. The site also has breeding Northern Goshawks and Grasshopper Sparrows.

This Important Bird Area is composed of wildlife management area (WMA) and the surrounding wetlands that form part of the upper Assabet River drainage along Elizabeth Brook. The area is part of a flood-control scheme.

A medium-sized pond (Delaney Pond), with a dam at its southern shore, has local areas of emergent vegetation along the edges and is popular with anglers and hunters. The northern impoundment, less visited and less accessible to casual visitors, consists of several large sections of cattail marsh and another smaller pond (not part of the WMA) along the river.

The surrounding woodland is mixed and is atop several eskers. There are several good stands of hemlock and areas of bog, but forests are predominantly mixed White Pine and deciduous trees with a fern understory. At the southern end, there is a small area of grassland where the Grasshopper and Savannah sparrows breed. The southern end is mostly old farmland in various stages of succession with scrubby and grassy fields bordered by stands of trees.

The AllTrails website has a description and map of a hike at Delaney Pond.