What's With the Trail Signage in CA State Parks

Disclaimer: I greatly enjoy California's state park system and I realize that it faces under-appreciated challenges, like for example that 50 parks will be closed as a result of the most recent state budget deal. That said - has anyone noticed that sometimes the signage and in particular the mileage is a little off? There are some markers at junctions around Castle Rock and the northern part of Big Basin that seem way off. If anyone has run back there with a GPS, I'd appreciate a yay or nay as to whether I'm right that the mileages are often way off.