http://www.sdsmt.edu/Admissions/Apply/Admissions-Requirements/ indicates that South Dakota School of Mines and Technology, a small engineering-focused school, will automatically admit a frosh applicant with a 2.75 HS GPA and 1130 SAT (580 math), and will consider for admission a frosh applicant with a 2.75 GPA and 940 SAT (480 math).
http://www.nmt.edu/undergraduate-admission-requirements indicates that New Mexico Institute of Mining and Technology, another small engineering-focused school, will admit a frosh applicant with a 2.5 HS GPA and 970 SAT.
There is, of course, the pathway of starting at a community college, doing well enough there, and then transferring to a four year school to complete an engineering degree, for students who do not have the high school record to attend an affordable four year school to begin with.