Although, every few years, US media reports that there is snow lying in all 50 US states, only 37 states have reliable enough snow to be able to operate ski lifts.
The 13 states which don't operate ski areas are Arkansas, Delaware, Florida, Georgia, Hawaii, Kansas, Kentucky, Louisiana, Mississippi, Nebraska, Oklahoma, South Carolina and Texas.
Several states have had ski areas in the past which no longer operate today including Georgia, Kentucky (where Arnie skied Ski Butler before it closed - meaning he has in fact skied 38 states) and Nebraska. A few of the others including Oklahoma also operate artificial surface slopes or temporary machine-made snow slopes.
Hawaii generally does have snow at its highest point on Mauna Kea which can be skied but there's no ski area or lifts.
Several of the 37 states that do still have ski areas have rather limited facilities. Alabama's one ski area, Cloudmont, for example, has only two basic lifts and a 46m vertical.