Can I become a snowboard instructor in America?

There are no visa availble for that type of work

You need to find an employer to sponsor you. A work visa like that is not something that you can apply to on your own. After that there is two paths. It all depends on whether you are coming here permanently or temporarly. If you are coming here permanently, your employer must first file a labor certification with the Department of Labor. The DOL will determine wheter the employer can hire someone from another country. The employer has to prove that they have tried to hire someone with the qualifications/education/training that they are looking for in that area and haven't been able to find them. If the DOL certifies the Labor Certification, then the employer can file a petition for you with USCIS. If they only want a temporary employee, nor labor certification is needed. They can just file for you with USCIS. Then USCIS sends the approved petition to the Department of State so they can interview you at an embassy. Anyway, I highly doubt any employer will go to all that trouble to hire a 15 year old snowboard instructor. Don't take it personally.

There are programs that will allow you to do this for a short period of time. They're usually for 3-4 months and are in summer camps, winter ski resorts etc. They will usually require that you have completed safety and first aid courses, can swim etc. Do a search for UK programs as they vary per country. I also think that you do have to be 18 to participate. These programs will NOT give you any type of permanent residency or provide a path to permanent residency and a green card.

such visas, in America, must be applied for by the intended employer and can only be issued if the employer shows that it is unable to find qualified Americans to do the work [ie: if there are a shortage of Americans qualified and available]. I doubt that includes snowboard instructors.

if they're willing to hire you

You need to find an employer to sponsor you. A work visa like that is not something that you can apply to on your own. After that there is two paths. It all depends on whether you are coming here permanently or temporarly. If you are coming here permanently, your employer must first file a labor certification with the Department of Labor. The DOL will determine wheter the employer can hire someone from another country. The employer has to prove that they have tried to hire someone with the qualifications/education/training that they are looking for in that area and haven't been able to find them. If the DOL certifies the Labor Certification, then the employer can file a petition for you with USCIS. If they only want a temporary employee, nor labor certification is needed. They can just file for you with USCIS. Then USCIS sends the approved petition to the Department of State so they can interview you at an embassy. Anyway, I highly doubt any employer will go to all that trouble to hire a 15 year old snowboard instructor. Don't take it personally.

There are programs that will allow you to do this for a short period of time. They're usually for 3-4 months and are in summer camps, winter ski resorts etc. They will usually require that you have completed safety and first aid courses, can swim etc. Do a search for UK programs as they vary per country. I also think that you do have to be 18 to participate. These programs will NOT give you any type of permanent residency or provide a path to permanent residency and a green card.

such visas, in America, must be applied for by the intended employer and can only be issued if the employer shows that it is unable to find qualified Americans to do the work [ie: if there are a shortage of Americans qualified and available]. I doubt that includes snowboard instructors.

if they're willing to hire you