What species of snail is this?
It resembles Cepaea nemoralis, or commonly called Grove Snail, belonging to the family Helicidae.



Image Source: WikiMedia Commons

According to Wikipedia, these snails were introduced to North America from Europe. These fascinating creatures occur in diverse forms of shell color as well, as shown below.



Image Source: Metodologie di Programmazione

Here I have found a very detailed shell and body markers for Cepaea nemoralis.



Image Source: ResearchGate