Karen,

Thanks so much for taking time out to walk with us today.  I must
have misplaced the little notes where I was jotting down some
thoughts, but luckily I got your email address from Wendy, and can
probably reconstruct most of my notes from memory.

One young tree we looked at, with knarled branches which we thought
might be a bur oak - we found a similar tree on the other side of the
river, with a thick pod hanging on a twig, so we think it's
Gymnocladus dioica, Kentucky Coffee Tree.  We also saw more sumacs
up the river, with obviously hairy stems, so they must be Rhus
typhina; the other kind must be R. glabra.  Also saw palm-leaved
shrubs, like buckeyes, must be Aesculus parviflora, Bottlebrush
Buckeye.  Wendy also found a Ginkgo, probably a male!

Can you find out more about the blight that's infesting the
Pinus nigra?  The nematode disease I talked about I think affects
mostly P. sylvestris, and is called Pine Wilt.  A "blight" probably
means a fungus instead?  I would also be interested in whatever
they find out about the hydrology of the Centennial Beach area.
Do you have any info on the topography of the Riverwalk area?
At the west end where Jefferson Ave crosses the river, we can see
a fairly steep grade from the bridge eastward; I would think that
marks an edge of the West Chicago moraine.  Do you have any data
on the kind of soil that underlies the Riverwalk?  If it lies on
the moraine, I would imagine there's gravel?  We saw some rocks
along portions of the walk, I wonder if some are glacial erratics?
Another question I had was what kind of Dolomite was excavated from
the quarries (i.e. were they Sugar Run or Racine formation), and what
were they used for?  Did people find fossils in the rocks?

Towards the west end of the trail we found many trees with tags
on them; is there a record somewhere about these trees?  We also
saw some bird boxes on a few trees, any idea what kind those are,
and who put them there?  Also there's a small marsh in the woodland
near the west end, any background info on how it came to be there?

Thanks again for a lot of valuable insights you brought to our hike;
I hope you don't mind my asking more questions!  And I look forward
to more opportunities to explore Park District trails.

Peter Chen
630-357-2338