F-500 – This class is for all adult riders and uses standard F-500 rules and regulations. This is a spec class utilizing 89 to 92 Polaris Indy 500 Chassis and Engine packages. Certain modifications are allowed, but the class is primarily stock in nature. This class is open for Junior Advancement procedures if a Junior rider so desires to enter the class.

F-500 Women – This is a F-500 class for competition for women racers. It uses all the same rules as regular F-500. This class is open for Junior Advancement procedures if a Junior rider so desires to enter the class.

F-500 Sport – This class is for beginning riders in F-500 and at the end of season high points drivers in the class will be advanced to the regular F-500 class. This class uses standard F-500 rules and procedures. This class is open for Junior Advancement procedures if a Junior rider so desires to enter the class.

Limited 500 – This class is a 500-cc engine volume class with relatively stock engine packages and an Open chassis design. It is a stepping stone to Champ classes giving the rider the ability to learn the nuances of an open chassis, while still in a controlled horsepower atmosphere. This class is very exciting to watch and runs very competitive lap times. This class is under review for participation levels that may affect future offering of the class.

Sportsman 600 – This class is a 2000 model and older class that allows certain modifications to engine and chassis. It allows for builder creativity, while total financial outlay is controlled by limitations to engine development and specific chassis limitations.

Factory 600– Factory 600 is a stock class featuring the newest production equipment, with fuel injected 600 cc engines and stock chassis. These sleds are extremely fast and are the newest of the highly competitive offerings from the manufacturers. These sleds and drivers made their debut on the Oval Enduro circuit for the past few seasons, along with also competing in the cross country circuits, especially on lake ice racing distance events. Watch for some special factory backed efforts this season.

Outlaw – This class is a single-track cockpit style sled, utilizing a full roll cage and other automotive aspects in its design. The engine packages are late model 600 cc engines and are limited in carburetion and exhaust. This class also is limited in traction controls and devices and is extremely exciting to watch, due to the Sprint car style of racing that the class lends itself to. Developed in the East by John Hooper, this class has grown most aggressively in the Midwest, and has a large USSA following.

Pro Lite – This is the entry level for the Champ class and offers a starter division for aspiring riders. All rules for the chassis are similar to Champ, however, exotic metals, and other costly components are limited. The engine package for this class is a 440 Stock qualified motor with little modification to further reduce costs and development time.

Champ 440 – This is an open chassis, 440 cc engine volume limit class and the PROSTAR CUP class. It offers the fastest competition on the ice. The sleds are based on all new technology and have few restrictions. While expensive to design and build, this class is the premier oval class in the world and is the most competitive of many forms of racing. The drivers are true athletes, and physical endurance along with strength are the defining driver attributes. Engine and chassis builders offer specialty, highly technical designs for competition in this class. The class offers truly the “best of the best”, in hard ice racing.

Vintage Classes

340 Super Stock – This class is derived from any stock qualified 340 cc (358 Max.) displacement, leaf spring front suspension model from model year 1985 or older. Air cooled and Liquid cooled engines will compete together in this class.

440 Super Stock – This class is derived from any stock qualified 440 cc (464 Max.) displacement, leaf spring front suspension model from model year 1985 or older. Air cooled and Liquid cooled engines will compete together in this class.

340 Super Mod – This class is derived from any 1985 or older Stock Qualified 340 cc (358 Max.) displacement, leaf spring front suspension model. Specific engine mods are allowed.

440 Super Mod – This class is derived from 1985 or older Stock Qualified 440 cc (464 Max) displacement, leaf spring front suspension model. Specific engine mods are allowed. Specific front suspension mods allowed. This is the current Worlds Championship class.

340 Sno Pro IFS – Only 1982 or older IFS single track limited production OEM racing snowmobiles allowed. No non-OEM, aftermarket or custom designs allowed. 340 cc (358 Max.) engine displacement engines only.

Junior Classes

Junior I Stock – This is a class with spec sleds from each brand along with certain designations for engine and control packages. It is an age 12 and 13 class using stock chassis and engines.

Junior II Stock- This is a class with spec sleds from each brand along with certain designations for engine and control packages. It is an age 14 thru 16 class using stock chassis and engines, same as used in Junior I Stock. This class may or may not be offered at various events. Check the registration form for availability.

Junior I F-500- This class is a restrictor plate class for F-500 riders aged 11-13. It uses all the basic rules for F-500 but uses a special designed restrictor plate to control speed and horsepower for the young advancing riders. Restrictor plates are available from USSA or ISR.

This class is a restricted class and is offered for young competitors to make a step into a somewhat modified class, while still retaining proper safety procedures. This class controls top speed and concentrates on handling and driver skill development.

Junior II F-500– This class is for advanced young riders and offers the speed and acceleration of Adult F-500 inside of an age appropriate learning area. Quite fast for the young competitors and very closely matched racing. This is a class for riders age 14-16 using F-500 rules and specs.

Junior I Sprint– This is a highly modified chassis class using an open chassis, and a controlled engine (stock block) package with only pipe and carb mods. Extremely fast for the competitors and fun and exciting to watch. Spec engines up to 380 cc volume air cooled engines are used in this class.

Junior II Sprint- The fastest of the Junior classes, using an open chassis and up to 600 cc in volume air cooled engines. This class has produced many of the now top adult riders including several World Champions in Champ class. Nick Van Strydonk and other Champions have matriculated through this class.

Youth Classes

Semi Pro 206 – This class is for 120 class snowmobiles with a spec Briggs and Stratton engine for equalization and builder affordability purposes. It is based off Stock 120 rules and is available to riders 6 years of age or older. In USSA this class is raced on the standard oval track used by the adult racers.

Pro 206 – This is a 120 based class and is for riders 7 years and older. This class uses chassis rules the same as 120 Sprint, with a spec 206 Briggs power plant. In USSA this class is raced on the standard oval track used by the adult racers.

200 Stock – A stock based 200 class featuring the newest of the factory offerings for youth riders.

200 Improved – A modified class for 200 class riders which will debut this year.