The Center for Career & Professional Development (CCPD) has a physical list of various opportunities that are available. You can also explore the following possibilities online:
- AMS – Internship & Co-op Opportunites for Undergraduates
- ASA – Internship Opportunities in Statistics
- FBI – Employment Opportunities
- Tech Interns – Undergraduate Science & Engineering Internships
These links will take you to the program descriptions of various summer job and internship opportunities, several of which we have had past mathematics majors successfully pursue. All of these programs provide a stipend and most provide housing and transportation allowances as well.