Women make up nearly 60 percent of United States college graduates – yet they comprise less than a quarter of U.S.-based professionals in the science, technology, engineering and math (STEM) fields.

A lack of financially rewarding job opportunities is not the problem. The U.S. Department of Labor projects that 15 out of the 20 fastest growing occupations in 2014 will require science or mathematics training. And a report released by the U.S. Department of Commerce says that women in STEM jobs earn 33 percent more than women in non-STEM jobs.

So, how do we inspire today’s female graduates to be tomorrow’s STEM leaders?

Simply ensuring that students take math and science classes in school is not enough. A healthy STEM education pipeline spanning kindergarten through higher education must be complemented by hands-on exposure to these subjects. This combination is vital not only to encouraging girls to take up careers in these fields, but also to producing a workforce that can compete in the global marketplace.

This rings true to me personally: I was one of only four women in an undergraduate class of 80 chemical engineers at the University of Michigan. I thank my father who involved me in all kinds of “fix-it” projects, and my high school chemistry teacher who encouraged me to pursue my love of math and science.

For the past decade, the public sector, trade associations and education advocates have made one point clear: Girls’ achievements and interests in math and science are shaped by the world around them. For a girl to link an early interest in science to a career in engineering, it is important to be exposed at an early age to women who have chosen paths to STEM careers. A young girl’s exposure to successful, fulfilled women in STEM positions illustrates the myriad choices available to her to build a lifelong career from her interest in science.

One organization that offers girls exposure to female role models during their formative years is Techbridge, a non-profit based in Oakland, Calif., that aims to bridge this gap by inspiring girls to pursue their interests in STEM subjects. Since its founding in 2000, the organization has served approximately 10,000 girls in grades 5-12, offering after-school and summer programs with hands-on projects, role model pairing, and academic and career guidance. Girls build their own greenhouses, solar-powered lights, and structures that can withstand earthquakes — and even experience what it is like to find oil thousands of feet underground through interactive simulations. The high level of poise and confidence these girls display when presenting their work is striking.

And in addition to building innovative projects, they meet women who do this work every day. By partnering with companies like Chevron, Techbridge introduces girls to female role models who are excelling in STEM industries. Every year, female Chevron engineers serve as role models for the girls, giving them lessons on geology and computer science, discussing their career paths and current jobs, showing them how fulfilling and rewarding careers in STEM can be, and dispelling stereotypes about women in these fields.

Research has shown that programs like Techbridge that combine role models and real world exposure of STEM to middle and high school students have measureable and successful results. A 2011 evaluation found that 83 percent of Techbridge participants surveyed were more interested in STEM careers because of role models and field trips. In addition, 87 percent felt more confident trying new things, and 90 percent said they believed engineering is a good career for women.

At Chevron, our global competitiveness depends on a STEM-proficient workforce that is dedicated to using their knowledge today to address the issues of tomorrow. Our employees have the resources to inspire girls’ interest during their formative years, and cultivate young women’s professional talents throughout their educational paths. By partnering with the public education system, we can address this problem head on, motivate interest in STEM subjects and professional tracts, and expand the prospective STEM pipeline.

My hope for today’s young women is that they fully realize that they can contribute to any field they love. Together we can reinforce that the sky is the limit for generations of girls to come.

Jane Doty MacKenzie is the general manager for Global Workforce Development at Chevron. Jane holds a Bachelor of Science degree in Chemical Engineering from the University of Michigan, and a Master's degree in Business Administration from the University of California at Berkeley. She also serves on the Board of Directors for Techbridge.

All statements and opinions expressed on this blog are those of the individual contributors, and not of the Bill & Melinda Gates Foundation or NBC News.