The Eagle County Sheriff's Office said 22-year-old Allison Marcus and 23-year-old Richard Miller of El Jebel turned themselves in Sunday.
They were being held on $7,500 bond each.
Sheriff's spokeswoman Jessie Porter says in a statement that Marcus and Miller face felony charges that include fourth-degree arson. It wasn't immediately known if the two had attorneys.
The Aspen Times cites an arrest warrant affidavit as saying the two allegedly were firing incendiary tracer rounds near Basalt when the fire erupted.
The fire destroyed three homes. It charred nearly 11 square miles and was nearly 60 percent contained Sunday.