" You use dans le with masculine regions/states/counties starting with a consonant."

Bonjour K, I noticed your amended question regarding counties and it appears that possibly counties refer to the English counties such as York, Cumbria, Hertfordshire, Norfolk, Northamptonshire, Oxfordshire, etc. I find no reference to counties in the US. For example, in Texas, Dallas is in Dallas county, Houston in Harris county and Austin in Hayes, Travis and Williamson. So similarly to your question, I am curious to know if US counties are also masculin. J'espère que cela vous aiderait. Bonne chance