Prof. Peer said that he was 15 minutes into his guest lecture when a group of protesters entered the room with banners and flags.
Haley, the last remaining rival to frontrunner Trump for the Republican presidential nomination, was the only major Republican candidate contesting the party's Nevada primary on Tuesday.
Conservationists and local tribal groups, whose land the mining takes place on, objected to the project.
Access to and from Black Rock City, the event site, was closed "for the remainder of the event," organizers said in a statement on social media.