Rocky Mountain oysters, also known as prairie oysters or calf fries, are part of the wondrous meat classification called offal. Rocky Mountain oysters share this distinction with other questionable but edible animal by-products such as chicken gizzards, beef tripe and pork intestines, or chitlins. Rocky Mountain oysters are actually the testicles of bulls or sheep. They are usually sliced, breaded, deep-fried and served as appetizers in certain restaurants. Don't forget the dipping sauce.

Rocky Mountain oysters earned their name through association with the prevalent cattle industry in the Rocky Mountain region, as well as a passing resemblance to raw sea-based oysters. A number of cattle ranchers regularly removed the testicles of young bulls in order to discourage aggressive behavior. Meat packing plants also saved the testicles of older cattle for possible resale as a meat by-product.

The first recorded preparation of Rocky Mountain oysters is clouded by history, but it seems likely that ranch cooks experimented with different meats to find inexpensive sources of food. When properly seasoned and breaded, Rocky Mountain oysters are said to have a neutral or slightly liver-like flavor, with a chewy texture similar to chicken gizzards. Restaurants serving modern day Rocky Mountain oysters are likely to use a generous supply of salt, black pepper, cayenne pepper and seasoned salt in a flour breading.

Preparation of Rocky Mountain oysters can be a little complicated. Obtaining fresh bull testicles is the first hurdle. Specialized butcher shops may be able to order a small supply, but in general, the product is sold in freezer packs.

Some recipes for Rocky Mountain oysters suggest slicing the testicles while they are still frozen for better results. Sometimes, the testicles arrive with a surrounding membrane, which must be removed before preparation. Peeling Rocky Mountain oysters does make for an interesting answer to the question, "So how was your day?"

Rocky Mountain oysters are usually served as novelty appetizers in steakhouses or other restaurants with Western themes. Other recipes for calf fries or prairie oysters involve poaching or sauteeing, but the official Rocky Mountain oysters are almost always served as deep-fried slices. The dish is said to be an acquired taste, but not completely inedible. Many customers who order Rocky Mountain oysters use generous amounts of hot sauce or dipping sauces to enhance the flavor. If you should happen to discover Rocky Mountain oysters on a menu while on vacation, you can no longer claim ignorance as an excuse.