I hiked in on the Bradford Ridge Trail two weeks ago with no problems. Nice hike and nobody on the trail on a Thursday afternoon. I usually drive through Twin Peaks and take Grass Valley Road to Hwy 173, then down 173 to the trail. This portion of Hwy 173 is not plowed after it snows and can be difficult to get through if there is much snow. So, I don't usually go that way if there has been much snow. Only once have I encountered enough snow to cause me concern. There were icy snow spots in the morning that I got through in 4-wheel drive. These were slush in the afternoon and no problem. They may close a gate on 173 between Grass Valley Road and the trail, but I have never been there when it was closed.
Actually, I hope to hike in on Bradford Ridge this weekend some time. I expect any snow will have melted by then...... It's supposed to be a warm.
See you on the trail or at the springs!