• The Mathematical Sciences Research Institute (MSRI) at U.C. Berkeley
  sponsors an organization that provides a support structure for Math
  Circles − the National Association of Math Circles (NAMC).
  
  
• The Art of Problem Solving Foundation (AoPSF) helps to support the Santa Barbara
  Math Ellipse and several other Math Circles.
  It is affiliated with The Art of Problem Solving (AoPS), the premier online resource for
  top math students, which offers classes, a community forum, and lots more.
  
  
• SB Family School (SBFS) is the organizer of the Santa Barbara Math Ellipse.
  SB Family School also offers enrichment math classes, math teams, math camps
  and other math-related activities, for elementary to high school students in the
  Santa Barbara area.
  
  
• The American Regions Mathematics League (ARML) is a challenging high-school level
  contest known as "the World Series of mathematics competitions".
  The Santa Barbara Math Ellipse joins with other Southern California groups to form
  a few 15-member Southern California ARML teams under the direction of the
  Long Beach Math Circle (LBMC).