I would look for more, for sure, however I would limit how many I collected to just a couple or a few. I would also release them back into the wild after I had some progeny to work with or after a couple of years (the time it should take to breed a male back to momma to see if you get a 50-50 ratio of normals to stripes. This is because to me it is a question of bio-ethics. By collecting the snakes you are taking a certain amount of a unique gene out of the population. If there are few enough snakes with the gene, you may take out enough to push the population across the threshold of where the normal genotype becomes fixed and the striped genotype is lost. However, it may not simply be recessive and there may be a spetrum across which you have everything from fully striped to completely normal snakes.
Thanks again for the great picture.