Summer Mathematics Program at University of Utah
The Summer Mathematics Program at the University of Utah runs for three weeks. There are three parts to the program: a three-week class (Explorations in Number Theory), afternoon colloquium series, and a computer lab. Students will receive three university credits. Most students have just finished junior year.
The cost is approximately $250.
You can learn more here: http://www.math.utah.edu/hsp/desc.html