Tuohy is the new high school record holder at 3000 but Mary Cain ran a better equivalent performance at 2 full miles indoors at the 2013 New Balance Indoor Grand Prix. In that meet, Cain ran 9:38.68, which John Kellogg converts to an 8:55.82 for 3000 (Cain’s old HS record of 9:04.51 was actually an en-route time taken from that race, but Cain also ran a 9:02.10 for 3000 on an oversized indoor track).
And Cain was younger than Tuohy was when she ran her 2 mile. Today, Tuohy is 6,158 days old (16 years, 10 months, and 8 days) whereas Cain was nearly a full month younger when she ran her 9:38.68 as she was 6,130 days old (16 years, 9 months, and 10 days). It’s also worth pointing out that Cain’s 9:38.68 2-mile came in early February -- three weeks after her 9:02.10 3000.
And in terms of the greatest American women’s high school distance performance at any distance, that clearly is Mary Cain’s 4:04.62 for 1500 that she ran later that summer at age 17. That equates to about an 8:48.91 for 3000.