Heat large nonstick skillet over medium heat until hot. Add ground beef; cook 8 to 10 minutes, breaking into 3/4-inch crumbles and stirring occasionally. Remove from skillet with slotted spoon; pour off drippings. Return beef to skillet; add cheese; cook and stir 1 to 2 minutes or until cheese is melted.
Meanwhile, place 2 cups corn chips in 9-inch pie plate. Crush chips slightly to lay flat on bottom of pie plate.
Spoon beef mixture over crushed corn chips; press gently with back of spoon to form even layer. Top with remaining 1 cup corn chips and 1/2 cup salsa. Serve immediately.
To serve, cut pie into wedges and carefully remove with pie server. Top with additional salsa, as desired.