The causeway is an abandoned roadway that once spanned the lake. There’s a section that once had a bridge, which boaters now use to move back and forth between the southern and northern ends of the lake.

The bridge was washed out by high water and wind in 1929 and never replaced, according to Tony Geiss, deputy director of the Onondaga County Water Authority. The 100-yard area where people fish is located on the western side of the lake and is accessible from West Valley Road.

https://www.syracuse.com/outdoors/2012/06/cny_shoreline_hot_spots_the_ca.html