This narrow strip of land is an old Southern Pacific railroad right of way that ran in this direction for miles and at one point connected Niles and Tracy. The newer line to the west ostensibly accomplishes the same goal. Just to the northeast of the cache is an abandoned and fenced-off, badly burned (but kinda cool looking) former railroad bridge.
PLEASE use caution when ascending up to the cache. The best spot for parking should be along Ray Street, as the cache is inaccessible from First Street and there is no good parking on Tessa Place. Enjoy!
Congrats to nozy nabor as the FTF!