As many have said, I'm not sure what qualifies as "having come the furthest" but I think Maria Scavuzzo has a great story.
Maria was a high school runner with "talent" but it was rarely made manifest during that time. She owned PRs of 5:09 in the 1600, 11:18 in the 3200, and 19:37 in 5k cross country, but when it mattered, she typically folded. She was never an individual state qualifier in either track or cross country for Medina High School (in Medina, OH). She did run on a 4x800 state qualifying team.
It was always her dream to go to Miami University (Ohio) and after incessant pleading and badgering, the coach let her walk on. Her freshman year left a lot to be desired. In her first cross country race she finished dead last, running over 26 minutes for 6k. Fast forward to outdoor track where she ran 39:56 in the 10,000m at the MAC championships and was dead last once again.
Things started clicking a little bit her sophomore year and after tanking in the 10,000 at the conference meet, she came back, seeded last, in the 5,000 and sniped 8th place, scoring 1 point and running a PR of 17:12.
The next year in cross country she grabbed the last qualifying spot out of the Great Lakes Region and was an individual NCAA qualifier, something that would have seemed impossible to most just a year before. She continued to lower her PRs but was majorly sidelined by a stress fracture late in her outdoor season.
Now, in her senior year of track, and three years after finishing dead-last and running nearly 40 minutes in the 10k at the conference meet, things came full-circle. She won the 10k with a big PB of 33:35 (17:10-16:25), which was also a conference meet record.
Upon graduating she knew she still wanted to keep at it and felt that even though she had come a long way and achieved a lot, there was more to be had. Even though her plate was full, as she was enrolling into a combined dietetics and dietetic internship program, she had an itch for trying her hand at the marathon. She debuted in Columbus this past October, running 2:37:52.
Another interesting tidbit is that in her four years at Miami, she had four different coaches!
I just love the fact that she always had a dream and inner-belief that she could be a great runner, even when her results seemed to clearly indicate otherwise.