Michigan SCEEP: http://cedo.engin.umich.edu/summer-engineering-academy/
Cornell CATALYST: https://www.engineering.cornell.edu/diversity/summer/high_school/catalyst/
Notre Dame Summer Scholars, Research Computing or Life Science Tracks: http://precollege.nd.edu/summer-scholars/
Georgia Tech SEI: http://ceed.gatech.edu/summer-engineering-institute-sei
MIT MathRoots: http://mathroots.mit.edu/
MIT LLRISE: https://www.ll.mit.edu/outreach/LLrise.html
Missouri S&T Materials Science: https://futurestudents.mst.edu/summercamps/materials/
I went to E2 and I want to emphasize that you don’t have to meet all the requirements to be accepted (other than the basics like rising senior and US citizen). However, be aware that the application is integrated with MITES and MOSTEC so even if you are accepted there’s still only a 1/3 chance of getting E2.