I'm hearing BLM Law repeater traffic on 171.750 (unit stating he was on the "Frost" repeater) in the Victorville area. The DB shows a different freq for BLM LE in So Calif. Does anyone know if this is the new output? This was analog traffic that I heard. Sometimes I hear P25 digital (unencrypted) but haven't confirmed yet what site that's coming from.
Are your sure it was the output? Are you sure it was the BLM? In the California desert nearly all the unit identifiers will have a 65, 66, 67, 68 or 69 prefix plus "R" and then a single or a double digit number, except for those who work out of the District office, which I think is located in Morenga Valley now and used to be in Riverside when I lived in the state. Their identifiers used to be in the 6200 series way back when I worked in Calif.
171.7500 is a very common Dept. of the Interior frequency as far as use. Most of the time it is used by the NPS. In CA it is used at Cabrillo, Lava Beds and Devils Postpile National Monuments. It used to be the backcountry net frequency at Sequoia-Kings Canyon NP's.
The old 166.7500 frequency had to be changed as it falls in the simplex range for the 2019 NTIA redbook directives. I don't travel much in southern California so I can't help at all with monitoring. I was taking some trips to SOCAL for a number of years, but the kids graduated from college out there so I'm not going there anymore. I used to take my BK radio with me until the 57 bug bit me in the butt and I had to retire.