My original idea was a hopper door latch as the line was temporary 3 foot gauge railroad built in the 1920's to mine gravel from a creekbed to build one of the first concrete roads in the area. With all of our winter rains this year this piece was exposed yesterday as was a spike.
There used to be oddball pieces of "snap track" laying around after it was abandoned (the last disappeared about two years ago shortly after I photographed it). There's now a bike path built over the old ROW and from time to time artifacts erode out of the grade.
Interestingly, when the bike path was constructed about 40 years ago, they did not grade the old ROW down to bare earth and in many places wood ties were left in place that have since rotted and caused their location to be revealed as the bike path slumped into the cavity left by the tie.