It is quite likely that no Death Certificate exists for Lena. The State of Montana did not insist that birth or death records be recorded at the local county courthouse until about 1920. If one was recorded at the county courthouse where she resided in 1902 and was not lost through the years, it should be filed with the Dept. of Public Health and Human Services, Vital Statistics division located in Helena, Montana. If a certificate does exist, they would have it. Go to the following website and scroll down to the bottom where you can download a copy of the application form to obtain a copy of a death certificate:

http://vhsp.dphhs.mt.gov/certificates/ordercertificates.shtm...

Hope this helps.