One possible stone pile and stone (boulder?) wall explanation:
“Working your way up the hill, you will begin to notice small boulders of broken off basalt lying on the ground. The small boulders of basalt indicate that you are re-entering an area of the park through which the feeder dike to the Hartford Basin runs.
At the top of the hill along the red trail there is an area that may have once been a site for mining. There are several small depressions still visible on the ground. In fact, these small depressions have rock piles nearby which indicate mining activity probably occurred in the 1800s (Figure 6 & 7). Mining activity may have played a role in the formation of several stonewalls that line the site.
The stonewalls may have been constructed from loose boulders
that were excavated during mining activity.
Records from this time period, however, are not available to validate this belief.
Also, close to these depressions, where the yellow trail and blue trail meet,
is a beautiful stone lined native spring through which water naturally flows (Figure 8).
As you exit the park from the blue trail, you will walk through a small valley
that once may have served as a road to the mines.
For more information on the geology, biology, and historic features of Osbornedale State Park,
visit the Kellogg Environmental Center located at the park entrance.
(Paugussett was the name of a major village at a falls where the Naugatuck and Housatonic River met - could the stone lined spring, stone piles and walls of stone be of Indigenous origin?? I wonder...)
"Osbornedale State Park is located in the Naugatuck Valley hills just east of the Housatonic River in Derby and Ansonia, Connecticut. The land was once the lushly forested hunting grounds of the Paugussett Indians. Fur traders, such as John Wakeman in 1642, were the first people of European descent to move into the Indians' territory. Permanent settlers began arriving in the late 1650's. The land was gradually purchased from the Paugussetts for items such as clothing or cooking utensils. Because the European concept of property rights was not embodied in the Indian culture, the Indians often "sold" the same parcel of land several times. The new settlers cleared the land for farming and took advantage of their location on the Housatonic and Naugatuck Rivers by developing the area into a trading port, which at one time rivaled New Haven harbor. The name of the settlement, originally called "Paugussett" was changed to "Derby" in 1675 after Derbyshire, England, the former home of many colonists..."