Salt Lake County says it's one of 20 counties nationwide to win Triple A ratings for taxpayer-backed bonds.
The high marks from Fitch Ratings, Moody's Investor Service and Standard and Poor's mean lower interest rates.
Salt Lake County got its highest marks for general obligation debts, which are backed by tax revenues.
The agencies gave Double-A ratings for the county's lease-revenue bonds, which are backed by business income, not taxes.
Among recent projects Salt Lake County funded with bonds were senior centers in Draper, East Millcreek, Magna and Riverton, plus libraries in East Millcreek and West Jordan.
The latest ratings were issued as recently as last week. They get renewed each time the county goes to the bond market to borrow money.