Bigelow Hollow State Park is public recreation area in the town of Union, Connecticut, in the Quinebaug Highlands.

The park and forest are located in a large hollow or depression approximately 700' below the surrounding ridgelines.

[5] The park and forest have over 35 miles (56 km) of trails, including several around 92-acre (37 ha) Breakneck Pond,[6] a secluded lake only accessible by foot.

A boat launch and picnicking facilities are located on 25-acre (10 ha) Bigelow Pond[7] at the entrance to the park and on 287-acre (116 ha) Mashapaug Lake,[8] which is found near the end of the park's main road.

The streams, ponds and lakes feature stocked as well as native trout, small and large mouth bass and pickerel.