UC Santa Cruz: http://www.darkenergybiosphere.org/education-diversity/for-undergraduates/

UC Berkeley: https://e3s-center.berkeley.edu/education-diversity/education/undergraduate/

Kansas State: http://www.k-state.edu/grad/academics/surop/summer.html and https://www.phys.ksu.edu/reu/

Department of Energy, National Labs, multiple locations available https://science.energy.gov/wdts/cci/

Lawrence Livermore National Lab Search: http://scholars-llnl.ttcportals.com/

Lawrence Berkeley Fossil Energy http://education.lbl.gov/Programs/MLEF/index.html

NASA search engine: https://intern.nasa.gov/ossi/web/public/guest/searchOpps/

American Physical Society Listings: https://www.aps.org/careers/employment/internships.cfm

More opportunities: http://pathwaystoscience.org/programs.aspx?descriptorhub=SummerResearch_Summer Research Opportunity