I'm taking a guess at where these were taken but won't post it on here. If it is where I'm thinking I was there in 2019 and then never got to go back in 2020 nor 2021 due to land border closures for non-essential travel from Canada to the US. Looks like for May 2022 I will get to go back as land border opens next month!!
I think you guessed it correct. I too went in end of April 2019, but it was bit earlier than the actual season of this fox. This year it was bit late(first week of June) but still I was lucky enough to see them around the den. Best time to see them is 2nd or 3rd week of May I guess.