The 37-acre Margaret Robbins Mills Crooked Spring Brook Reservation was the first property purchased by the Conservation Commission. It was purchased in 1965 from the Snow family and was renamed in 1993 for the former Conservation Commissioner Margaret Mills, who led the acquisition effort. This reservation is located in West Chelmsford, between Crooked Spring Road and Graniteville Road, and is surrounded by residential neighborhoods. There are several trails on the property, most of which connect to the main trail. The main trail begins at the parking lot on Crooked Spring Road and generally skirts the wetlands on the property. Pedestrian access is also available in two locations from Graniteville Road, although there are no parking facilities. The trails on the property are clear and bridges and boardwalks have been installed across several wet areas. Among the interesting features is a pond suitable for fishing and skating. There is a great diversity of wildlife at the Mills Reservation, including white-tailed deer, red fox, beaver, muskrat, ducks, and others. In the spring pink lady’s slippers can be observed on the hillside along the eastern leg of the main trail. They are just one of several plant species that create a dense ground cover in this area.

The AllTrails website has a description and map of a hike at Crooked Spring Reservation.