I have zero experience with California laws and did not know that a handler of a HRD dog is required to be paid. Interesting. I do know that an itemized list of search missions is required for most counties right down to the cost of the fuel that was used for vehicles. Seeing the actual grand total at the end would shock many people.
Enough of my rambling and this is all my opinion
I don't know that the handlers have to be paid. In fact, all of my experience is the same as yours - the handlers are volunteers and are not paid. If I implied otherwise, I obviously chose the wrong words.
However, I have never heard of a case where the handlers paid for their own hotels, transportation and expenses. These can be considerable (and sometimes include airfare).
The County pays for those things. And they would be significant, given that the search area is in the middle of nowhere. In my county, the County pays for SAR gasoline, expenses and liability insurance. In an ongoing search, they also pay for and provide meals. The SAR volunteers are not expected to bring their own food, and any equipment that is one time use is paid for by the County. I agree with you that people would be surprised at how quickly the costs add up.
Still, didn't we hear that Barbara's search cost $80,000? I've seen that figure here, but now I don't know where it came from - perhaps just an estimate of $10,000 a day (given that air support was involved on several days, that's not surprising).
In 2016, when SBSCO had a big fire, they brought in teams of dogs from San Diego County (which has a few teams of cadaver dogs). I think San Bernardino does have a team of its own, but cadaver dogs are few and far between, and I can't say that with certainty. I know that SD's dogs are in high demand. They were flown into the Paradise fire area and their teams were housed nearby (hotels) and fed. My own county uses dogs from Santa Barbara County and San Diego County.
San Bernardino's own volunteer handlers/canine units traveled 76,000 miles in 2018. The reimbursement rate is established by law and policy at the County level. The reporter who gathered that information probably just took it from public records (easiest way to get it).
I'll try to find out how many SAR dogs SBerd has, of its own. I count 8 of them in a team picture probably taken in 2016. San Bernardino, where the equipment is housed and deployed for most searches, is 2.5 hours away from the search site. Hard to say where the handlers live, but no one much lives near Kelbaker road, so I'm assuming they either gather and deploy from County HQ, a 5 hour daily round trip for the handlers, not counting search time (and they had to get there early in the morning for heat not to be a major factor) OR they stay in motels closer to the search site. Ludlow is only 40 minutes away and has at least one motel. My friends in SAR stay in cheap motels. When it's a training exercise, they pay their own expenses. When it's an actual search, the LE entity puts them up. Sometimes the accommodations are tents, but I don't think that was the case in the Mojave in July.
I just think that the logistics of this search might have required handlers to either travel 5 hours round trip (in pre dawn or post dusk hours) and that sort of thing affects length of time for the search (again, covering just 1 square mile would be at least a day's work; for cadaver searches, they need to search further - it would be a few days of searching, driving 5 hours every day would take its toll on dogs and handlers alike, which makes the search less reliable). But that's a lot of gas (and if the handlers are not from actual San Bernardino, there would still be accommodation costs). Handlers travel with quite a bit of dog gear but apparently use a variety of personal vehicle types.
The overnight lows were in the 90's out there (at 5 am). It was still in the upper 90's at midnight according to the Desert Research Center data.
I sure hope that there was a human remains recovery dog among the dogs brought out there.