What's sad is that a single year grade skip is so "rare" in their elementary school. It's hard to believe it was really enough for them at the time - obviously since that time they accelerated through a couple years' worth of math if they managed to be in geometry in 7th grade (it looks like their age was sixth grade at the time that they took geometry - must have been 11, I guess).
Shasta Middle School has 600 students - its one of only two schools in that school district. And the Eugene MSA has about 300K people living in it. So, I would imagine these kids are kind of rare given both the size of the district and the nature of Eugene's demographics.
I lived in Portland when in Middle School. It is a great town for MG/PG kids due to the excellent public transportation and lots of stuff going on. Via showing up at club meetings of topics I liked, I lucked out and met adults who understood me. The school districts back then were just getting going on "TAG" programs. Most of them were not in-depth or challenging enough and were aimed more at the top 5%, not the 5/10% of 1%.
In this article, it really sounds like the dad is the driving force behind his kids' success, not necessarily the schools.
Hats off to the school district for being flexible.