This one is kind of strange. No promo tokens from ERV are listed in the Nevada Promo Token reference. This one is marked sterling on the (plain) edge and appears to have been artificially toned as it's quite even over both sides and the edge.

I consider it rare, and would appreciate any background that could be supplied. It's always possible it's a modern souvenir but it doesn't look like any of the 1973 silver casino medals that were produced.

Anyway, nice to have something that associates Wilbur Clark with El Rancho Vegas as well as Desert Inn.