In most states, an adoptee is given an amended birth certificate with the adoptive name on it. It may be a birth card or short-form transcript with limited information. The adoptee wants the full copy version of the amended birth certificate---it contains the names of the adoptive parents and has a space in which the hospital of birth may or may not be named. The city where birth occurred is usually truthful.
The adoptee can ask the hospital (if any) if they destroyed the medical records from the time period in which she was born. If not destroyed, do they have a date-of-birth index to identify a record even if the birth name is unknown? I know of an adoptee who received a packet of information from her hospital, with valuable information, and a bill for $55.00 for reproduction of records. There is little feedback from adoptees about medical records to be found on the message boards. There may also be admission records and financial records, about which even less is known.
Fargo (if that is your birthplace) is in Cass County. The Handy Book for Genealogists has no information on a local registrar that might have copies of birth certificates. In other counties, clerks of district courts have such records.
I do not know if the local registrar in Cass County (phone 701-241-5645 is for the clerk of District Court in Fargo) was notified of your adoption so that he could seal the original birth record. If the original consisted of a photostat on a separate piece of paper, he could readily remove it and relocate it to a sealed file in a safe or special file cabinet.
However, if his copy consisted of a manuscript entry in a big book called a liber, how could he seal it? I think he would attach an amended version on a slip of paper and staple it to the page of the liber to cover the original entry. I don't know if genealogists have free access to the libers, but you can find genealogists on the message board for Cass County here at Ancestry.com :
http://boards.ancestry.com/mbexec?htx=board&r=an&p=l...Good luck from [Mr.] Reg Niles