Near South East Street much of the wooded Sanctuary property floods in spring. The trail loop in this section may be impassable for parts of the year, especially after heavy rains.
This low-lying area was the floor of Lake Hitchcock, a large glacial lake that formed when the ice sheets retreated north from Amherst approximately 15,000 years ago. Fine clay accumulated on the lake bottom making for poor drainage today. The Connecticut Valley 15,000 years ago exhibit at the Beneski Museum of Natural History has a reconstruction of the Amherst region as it appeared when Lake Hitchcock was at its greatest extent.