Yes there are attorneys that specialize in foreclosure, I might hire one of them. They are easy to find using Google, and you would want a specialist. They charge less and do a great job. It is better to find a local service but not required. Any licensed CA attorney that specializes in forelclosure could do the job.
That said, I am about to go on and on, about what may be useless information and thoughts: but in case it is helpful.
Once you find out what the lawyers charge for this, if you are up to the task, depending on the situation, you might save some money and just hire a paralegal to file a notice of default. This needs to be published in a local paper, and is filed with the court and becomes a public record. Once you do that, the borrower will not be able to find a lender to refinance your note, so if you have received any requests for a pay off, you may want to hold off.
I would contact the borrower, maybe they are going through some kind of a temporary and drastic problem, a death or something? Contacting them, will also allow you to sum up the situation. Are there other liens foreclosing? I personally would not become a "Snidely Whiplash." In other words, it may be a tragic situation that you may want to be a bit merciful. Perhaps the owners have cancer and are dying. Your NOD may just shove them right over the edge and kill them. You wouldn't want that...or maybe they are nasty mean people and you may want to torment them as much as possible. I would call with a caring attitude and find out. (Actually you sound like you have already done that.) If all else fails, you can always tie them to the railway tracks.
Once you file the NOD, the owner of the property will get bombarded with offers to buy the property, that may solve your problem right there. You may get offers to buy your note. All be it at a discount usually, not always. Trust me, they will have their phone ringing and have all kinds of truly obnoxious people pounding on their door starting most days at 6 in the morning. It used to take about 90 days to foreclose, I know they have changed it.
Remember they can file chapter 13 and put you off for a year or more. Another reason for calling them in person and assessing the situation. So if they are dying of cancer and the NOD does not kill them, the imbeciles knocking on their door at all hours will finish them off for sure. I am guessing you may be considering, going over there and killing them yourself. I would consult your attorney first, there could be legal consequences.
But, remember what the police say, "no good deed shall go unpunished," If they are dying of cancer, and you do not foreclose, it may be a probate you are dealing with. Of course the probate court will have to approve your foreclosure and they can take 9 months to give you a preliminary hearing.
Being it may be the property is a bit rural, it is less likely to be bombarded, so the attorney may be the way to go, as you may need someone to carry it through to the end.
You do want to be careful, if there is a lien holder that is senior to yours that forecloses and you miss it, then you could lose your lien. For about $75 there are services that will notify you. You may want to call the county tax assessor and see if anyone else is foreclosing. Ask them if there is a service to notify you.
They are usually very slow to foreclose based on tax liens. It sounds like you have a first, If you have a 2nd lien and a first forecloses before you, you could have your lien dismissed, it would become personal debt to the borrower. This may be better if the property is upside down, as you can then get a judgement for the full amount, that lasts for 10 years and then renew it for another 10 years if the world does not end before that. Based on our choices for president, either way it goes, it may just end.
On the other hand if you foreclose, you will also need to pay the taxes and any senior liens. You may not be prepared to have more money going into this. It sounds like you are.
It sounds like you have already, but I would also determine the present value of the property, the easy way is to take the value provided by Trulia or Zillow and adjust for the condition, knowing that Trulia and Zillow will usually give you the average value of the average house in average condition in that area. Having this information will help you decide the best course of action.
Do not take this instead of any legal advice I am not a lawyer. I do not envy your situation and hope it works out for you.