That's curious since they were so widely photographed. If a chaser misses one or two of these opportunities, much of the season may be lost. For the plains states there were four of these big events in 1997, one of which I missed, occurred at Jarrell, Texas. A day that I chose not to chase produced a large tornado at Shamrock, Texas. Also, a good argument may be made that both the Lubbock area tornadoes of April 10th, and the Jarrell tornado were on the fringe of chase country for most participants.
Many chasers have a window of opportunity to get to the plains each year.
It's a gamble to pick the correct time frame. The statistics point to the last two weeks in May, but that doesn't always work. There were no disasters during 1997 like being flooded out, buried in the mud up to the wheel wells or getting the windshield blasted by baseball hail. I did get banged up pretty bad in Nebraska on June 30th when a dirt road shoulder gave way, sending me for a ride in the field with the cows.