Since 1953, General Motors has been testing cars and trucks under development at its Desert Proving Ground southeast of Mesa. And for 50 years, the fences have been high and the gates closed to keep spying eyes from seeing the new cars and trucks before they hit the showroom.

But on March 9, General Motors opened the gates to classic clubs representing every GM make, along with other invited guests, to celebrate the Proving Ground’s 50th anniversary. And for the first time, GM allowed cameras inside the facility.

Arizona Impalas brought 14 cars to the party, including Karl & Cindy Becker’s 64 Impala SS, Dan & Patricia DeSantis’ 66 Impala SS, Jack Donovan’s 65 Impala convertible, Gary & Samantha Dulude’s 64 Impala sport sedan, Bob Kohler’s 67 Impala sport coupe, Jerry & Arlene Lehr’s 66 Caprice, Jerry Montgomery’s 74 Impala Spirit of America, John Sahid’s 62 Biscayne 409, George & Devona Stebbins’ 64 Impala SS, Brian Vaughn’s 72 Impala convertible, Daryl Wimer’s 58 Impala sport coupe, and Vic Zavarella’s 65 Impala SS. Joining us for the day were Jim & Linda Bates with their 62 Impala SS 409, Paul Hoch’s 58 Bel Air, and Robbie & Michelle Robinson with a 64 Impala SS, that other than the fender skirts, is a dead ringer for Karl & Cindy’s car.

Classic GM clubs from throughout Arizona participated in the event, bringing hundreds of cars to display. Among the clubs attending were the Arizona Chevelle Club, Arizona Street Rod Association, Cactus GTO Club, Classic Chevys of Tucson, Desert Classic Chevys, Desert Corvette Association, Desert Renegades, First Generation Camaros of Arizona, Oldsmobile Club of Arizona, Southwest Allanté Group, Southwest Nova Club, and the Valley of the Sun Buick Club.

As each club’s caravan arrived at the Proving Ground, GM staff and volunteers directed the cars onto the road course, including a turn on the famous banked oval track. The high-speed lane (95 mph minimum) was blocked off by orange cones, but even in the slow lane, it was a once-in-a-lifetime experience.

Besides the classics on display, GM also brought several of its famous concept cars, including the jet-powered Firebirds of the late 50s and early 60s, the prototype for the mid-90s Impala SS, and the Cadillac Evoq parked next to its production version, the upcoming Cadillac XLR roadster.

2003 is also the 50th anniversary of the Corvette, with a white 1953 roadster, a 1978 Silver Anniversary coupe, and a 2003 50th Anniversary coupe sharing a display. In addition, Corvettes from every generation paraded down the Proving Ground’s main street, a phenomenal display of America’s greatest sports car.

The Corvette was also the star during several of the precision driving demonstrations given throughout the day. Perhaps the most spectacular stunt was two Corvettes going nose-to-nose, with the Corvette in reverse leading the way at full throttle. GM’s expert drivers also showed the effectiveness of anti-lock brakes and GM’s StabiliTrak stability control system. In the StabiliTrak demonstration, the driver threw a Cadillac STS into a skid, and the car corrected itself while the driver held his hands out the window to applause from the crowd.

Click here to see picture of the GM Proving Ground Driving Demonstrations.