ARGUED FEBRUARY 18, 2010
Before EASTERBROOK, Chief Judge, and KANNE and ROVNER, Circuit Judges.
Norberto Araujo entered into a plea agreement with the government in which he both acknowledged that his heroin trafficking involved a quantity of 30 or more kilograms of heroin and yet reserved the right to assert that he should be held to account for a lesser amount. He subsequently objected to the probation officer’s proposed finding that he was responsible for at least 30 kilograms of heroin, arguing that the evidence warranted a finding that his trafficking involved more than 10 but less than 30 kilograms. In response to the objection, the government cited, among other evidence, Araujo’s earlier proffer statement, in which Araujo had acknowledged the distribution of more than 30 kilograms of heroin. Based on Araujo’s factual admission in the plea agreement, his proffer, and alternatively based on independent evidence concerning the extent of his trafficking, the district court concluded that Araujo was responsible for distributing at least 30 kilograms of heroin. That finding triggered an advisory sentencing range of 235 to 293 months in prison. The court sentenced Araujo to the minimum recommended term of 235 months. Araujo appeals, con-tending that the plea agreement is unavoidably ambiguous on the subject of the drug quantity, that it was improper for the government and, in turn, the court to rely on his proffer to establish the drug quantity, and that the evidence otherwise did not support a finding that he trafficked in at least 30 kilograms of heroin. We affirm.