I wonder what the numbers 10 & 26 mean on the wingwalker pic?

Reference numbers of some kind?

Heel print = Evidence No 10
Toe impression = Evidence No 26

No idea, really – could be something else entirely.

I counted the lines in the heel portion of the pic of the impression and there are 10 lines. The lines in the other portion of the impression are harder to count but would suggest that there are 26 of them. I believe that is what the 10 and 26 refer to.

Tom, you’ve been to Berryessa and literally jumped on that ground to try and create boot impressions in the soil, and failed. Looking at all the weather data for September in Napa, there was no precipitation in September with temperatures that ranged from a maximum of 37 degrees to a minimum of 8 degrees. There is certainly no record of rain in the days before September 27th 1969. On that day the ground had baked in temperatures of over 25 degrees for most of the day. These footprints could have been anybody who had previously walked that route from parking area to shore. Do you believe it’s conceivable the footprints recorded and photographed that day could possibly have been made by the killer.

The was no rain in the preceding days in the run up to the Lake Berryessa attack and the mean daily temperature would have been 26 degrees, with an average high of 37 degrees. That make up of ground would have been scorched solid and bone dry. A man of 200-250 lbs could not have left boot impressions in the ground. I remember Tom Voigt and company visiting the site on a dry day and jumping up and down on it, yet failing to leave a single impression. Those impressions were most likely made in favorable conditions, shortly after precipitation and then baked dry by the sun. Impressions in moisture free conditions such as these are highly unlikely to generate such detail. Similarly no footwear impressions were found at Lake Herman Road, the ground was frozen solid, but this time in freezing temperatures rather than being baked dry.

http://www.wunderground.com/history/airport/KAPC/1969/9/25/MonthlyHistory.html?req_city=Napa&req_state=CA&req_statename=California&reqdb.zip=94558&reqdb.magic=1&reqdb.wmo=99999

I have to disagree with the assertion that it would not have been possible to leave footprints in dry conditions. Of coarse it would have been possible.

If tom had difficulty that does lend some credence to the claim, however, it does not mean that zodiac could not have left them.

Not just possible, it was a demonstrated fact, the Police replicated it just hours later.