The Palmerston 17-year-old set off to chase her dream in February and has notched up three championship wins, plus earned herself a mention on the Racer X website.
She took the spotlight with her performances at two major Texas races - the International Grand National Championships at Oak Hill and the James Stewart AMA Spring Championships at Freestone.
Racer X asked the amateur motocross experts at Vurbmoto.com to name the top 10 riders. This was what they said about Duncan:''You probably have not heard of Courtney Duncan, but the New Zealand transplant is looking to change that.
''She handily won three women's titles in Texas (including a come-from-way-behind moto win featuring a last-lap pass on supermini star Hannah Hodges), but she also raced with the boys in Freestone. A seventh in the schoolboy moto raised a few eyebrows, no doubt, and Duncan is definitely on our radar for 2013.''
Based at the Millsaps Training Facility, in Georgia, she is on the fast track to international improvement.
In a blog she writes for sponsor Backflips Clothing, in Timaru, she talks about Millsaps' credentials.
''The jumps are massive. To give you a rough idea, I don't think I've hucked bigger jumps than these in my entire life.
''The facility they have to offer here is unbelievable. Everything you need is right here. Not to mention how many fast riders are here also.''
Duncan spends nine hours a day, five days a week in structured training on her motorbike, undertaking fitness conditioning and learning how to develop mental skills and utilise nutrition.
She is approaching her long-held goal of competing in the Loretta Lynn Amateur Motocross National Championship - the world's largest amateur motocross race - on July 29.
Duncan is now focusing on the Hangtown Motocross Classic in California on May 18. She also has to qualify at an area and regional level to be able to ride at the Loretta Lynn event.
Duncan said, in an editorial she wrote for Kiwi Rider magazine, she knew she could not just click her fingers and ''go straight to the top''.
''It doesn't work like that. It's going to take time and a lot of hard work. I do believe it's possible, though, and that's what I'm working towards.
''I'm in the best place right now and with the programme we have going here, I think it's going to benefit me a lot and I should gain speed very fast.''
