SACNAS is the nation's
leading organization working to broaden participation across the
sciences. It is a welcoming space for undergraduate students,
graduate students, postdocs, and faculty. The National Alliance for Doctoral Studies in the Mathematical Sciences is the nation's leading mathematics specific organization working against underrepresentation. Undergraduate students can join the alliance and receive mentorship, undergraduate faculty can serve as mentors, and faculty at PhD granting institutions have many avenues for participation. The Algebra Project is a civil rights organization working to raise the floor of mathematics education in the US. Focusing at the High School level, the Algebra Project seeks to facilitate students to demand their own access to quality education in mathematics. We demand mathematics! The EMentoring Mathematics Network is an electronic publication hoping to support mathematicians through the various stages of their careers. Its goal is to reach as many readers as possible, especially those who may not have sufficient mentoring at their current institution. 
The local Claremont SACNAS Chapter is now forming. If you
are a student or faculty interested in working to broaden
participation in science, please join us! Stay up to date by joining
the Chapter's Facebook page above. The seminar SUMS (Seminar on Underrepresentation and the Mathematical Sciences) is an effort to discuss and confront the myriad issues surrounding gender inequity and underrepresentation as we work toward diversity. Pathways is a Los Angeles area mathematics outreach program based in the Department of Mathematics at Harvey Mudd College. All of our volunteers are professional mathematicians who are eager to share their love of mathematics with elementary, junior high, and high school students. Imagine Math Day is a day of mathematical activities, exploration and inquiry designed for high school mathematics teachers and students. If you are interested in outreach to the local community, this is a great opportunity. The Office of Institutional Diversity is a good resource for comprehensive information related to diversity at HMC. 
The Annual Survey of the American Mathematical
Society is the best source for timely information regarding the
mathematics professoriate. See the link above for current
employment statistics, and PhD demographics. The Gathering Storm is a definitive report of the National Academies. A free PDF is available at the link above. They describe the current and projected needs of the US workforce, and describe in detail our need for working against gender inequity and underrepresentation in science. 
There are several REU's working to broaden participation in
mathematics. These include MSRIUp and MTBI, among others.
