At high altitude with snowy winters are Oyster Shells the preferred surface for a Bocce court?

I really couldn’t say…You may want to try asking someone at a local hardware store or a sporting goods store.  Good luck!

“We had a customer today inquiring as to how many 50 pound bags he would need to buy for a 500 square foot court 1 1/2 to 2 inches deep.  At that rate you would require about 215 bags. 
If you want to do your own calculations the bag measures 21”” x 12”” x 2”“.  Good luck!”