unknown snake in wyoming

Question
My family and I where walking the path of cook lake in Sundance wy . My son kept stopping to pick up rocks , my husband was in front and my son was in the middle I was in back . My son stopped again and I thought he had stopped to pick up a rock and when I got to him to get him up off the path and keep walking . I looked down and he had dropped a snake . but I thought at first it was  a night crawler . to my surprise it was a very small snake maybe 6 inches about the size of a large night crawler , I pulled my son back and and grabbed the snake by the tail and lifted him up and to my surprise I have never seen a snake like this in my life , I could not take a picture of it before i dropped it again .I was scared he might bite me but i needed to see what it was in case it had bitten my son i could identify it . The snake was around 6 inches long and was a deep silver almost blue and the crazy part was his abdomen , it was striped long way from head to tail , one big electric blue strip down the middle (thick), and there where 2 hot pink stripes going down each side of the blue stripe . And his head looked kinda square , this happened so fast . but i have been looking all over the internet for 2 weeks now and i can not find even a similar photo of this snake anywhere. it has the similar color of a Ring neck snake on top , and its not a blue racer , the colors on his belly really caught my attention .I really need to know what kind of snake this was because i can not figure it out  . No one in wyoming has seen or heard of a snake like this .could you please help me identify this very cool snake.so i can stop searching the WEB all night. thanks you for any help you could give me , P.S his colors where very vibrant hot pink and electric blue .  

Answer
The snake you saw is called a Wandering gartersnake, possibly a Western plains garter snake. They are quite variable, and what you describe fits well within that variation. Especially when they are young (6" would be a neonate), the pattern and coloration can be especially high contrast and strong.