Sure, it is an extreme long shot, but worth investigating, there are several cadaver dog orgs in the area. Dogs go down 10-15 ft, GPR much further, they also have the ones that are carried above ground.. no drag, no wheels
If somebody can map out a potential search area, we can contact them.. wouldn't cost much. Never know till you ask.
What you might find are newer corpses or pieces of corpses that have been buried. Its a large area. People suggested this to Tosaw and his team but for some reason he decided not to expand their search onto land. If you are going to search in and around Caterpillar Island then you are almost obliged to search inland in the whole Shillapoo area down to Vancouver Lake, because the whole area is part of the Columbia drainage basin. Dont forget, there were Hobo encampments in this area below the railroad line back in 71.
While it is true Tosaw's methods did not include 'digging' into the sand to any great depth, his theory was that currents and eddies deposit and then remove sand in the same areas, in seasonal cycles. Thus no need for digging. Tosaw tried to time his inspections of certain areas to match these seasonal cycles, based on advice he was getting from experienced locals and salvage people. Still, they did do some digging in areas of particular interest. Tosaw wasn't stupid - far from it! Rataczak played a role in setting this all up! But, Tosaw also talked to a number of Agents who had worked at Tena Bar in 1980 most of whom felt that the money had not traveled too far from some original source in the area. Few people believed Himmelsbach's Washougal account.
People suggested bringing cadaver dogs in in 1980 but I dont know if it was done.
There are still people alive who worked with Tosaw in his project who know the whole story including what Rataczak told (or did not tell) Richard at the time, and how reliable Richard thought that was. Richard talked to a number of people and consulted experts regarding the flight path. Richards interview sets forth the basics.