We rode in from a Yerington a few months ago. We were able to get all the way into Dayton with no issues. Should be public land all the way in. I remember a dog park along the way. This may not be the actual race course and finish line but it’s close and does access the road over Como.
I'm not sure how "Safe" you want your equipment but there is an industrial park you can ride from a couple blocks from the dirt. Also the dog park is at the edge of the pavement. I'm not sure about riding from further in town and parking at the Pizza Factory. Keeping in mind the dirt is only 3-4 blocks from hwy 50.
Pit 10 in Mina, yes, used that campground this year as the base for our pit there. Full hook-ups and clean bathrooms/showers. Folks who run it are nice and support off roaders as does all the town (what there is) of Mina. UTVs allowed on the streets and trails in and out of town. Only drawback is there is really nothing else there BUT the RV park and the hamburger stand and I believe the RV park is closed December and January and maybe later. They said they leave for about 3 months in the winter and head back to their roots in Cali. Cool retirees that hang at that place.