I just checked the historical weather page and did not see a huge storm in March of 2004, although there was a deep snowpack in that year well into March.
The latest I have ridden here was on May 1, back in 2009 I think. If you check my archived journals, you will see. I thought it was going to be somewhat of a "novelty" ride to say I rode in May in the UP, but ended up being a several hour, 20-30 mile ride through the backcountry. I could have rode in May back around 2 or 3 years ago too.
-John