The NARA records are not accessible online and will need to be requested by the specific NARA agency where records are stored. Using the link below you can see a list of all federally run schools that NARA has records for.
The schools listed below have records stored at NARA Washington DC:
Pennsylvania: Carlisle Indian School
Source: Navigating Record Group 75: BIA Schools. National Archives. Last reviewed on June 25, 2018. https://www.archives.gov/research/native-americans/bia-guide/schools