Since it seems like a lot of the traffic heard in Spanish is radiotelephone related, I decided to put together a list of all of the logged rural radiotelephone link frequencies:
All frequencies in kHz, mode listed with frequency
6835 USB - Spanish language, possible radiotelephone link (last logged Jan 2018)
6805 USB - Spanish language, possible radiotelephone link (last logged Jan 2018)
6799 USB - English language, YL and OM heard talking
6790 USB - Spanish language, possible radiotelephone link (last logged Jan 2018)
6786 USB - Logged several times, Spanish language
6780 USB - Confirmed rural radiotelephone service frequency
6775 USB - Alternate frequency, lots of offsets in this portion of the band (6777.5 kHz, 6767.6 kHz, etc)
6772.5 USB - Spanish language, OM and YL heard talking (last logged Jan 2018)
6768.5 USB - Spanish language, OM and YL, heard during band opening to South America
6767 USB - Logged several times
6765 USB - Heard during band opening to South America
6760 USB - Another presumed radiotelephone link frequency
6755 USB - Logged several times
6750 USB - Logged several times, Spanish language
6749 LSB - Spanish language, possible radiotelephone link (last logged March 2018)
6721 LSB - Spanish language, presumed radiotelephone link
6713 USB - Presumed radiotelephone link, possibly just freebanders or pescadores
6710 USB - Spanish language, presumed radiotelephone link
6705 USB - OM and YL talking, sounded like a telephone conversation (last logged Jan 2018)
6700 USB - UNID language heard here