Kodiak, Short answer is that it is elk activity and standard to the unit.
I had the type 9 tag a few years ago. It was also one of the first years that they offered a rifle tag early for cows and my dad had that tag. We ran into a similar situation in that area. My dad filled his tag but only after we got access to cross private to get to public. I never could make it work with a bow. Saw several very good bulls! Another area in the state is similar in the fact that the elk seem to be pretty visible prior to the season and then when the hunting starts they are gone. I personally think that the added pressure makes them move into more rugged areas and on to private where the pressure is much less ( you saw this). There are also some areas that they move to during the rut, it seems that they have all they need (Cover, Food, water, and less pressure) and even though they are still on public land, it is difficult to capitalize on them.
I can't really answer your question on the elk movement late season. We have hunted that area later on and with good success. It seems that the elk bunch up and head lower at specific times of the year and not necessarily due to the snow. Obviously, it helps when the snow gets deep up high.
