Thank you for the pics, del rio! I used Microsoft's latest 'Paint' app, simple but useful.
The 'disturbance' seemed out of place with my 'observations', that's why I labeled it as 'unknown'.
The 'tread mark' does not appear similar to most tire-made marks I've seen, and given your explanation I no longer have to stare at it to determine what the heck it is ... and it's even odd as an asphalt anomaly.
The 'possible blood' item is questionable, as it could be over-spray or a re-route of the flourescent paint.
The 'scrape' and 'drag' areas interest me the most ... the scrapes along the edge of the asphalt seem 'fresh', not dark / weathered and as if made by a flat, wide, metal sled ... but the ground (pic) shows no sign of wide area tamping. That edge show-out might not have anything to do with this case as I'm sure that route is used quite often when the house is occupied or when 'visitors' roam to the pond or shore area.
When LE originally stated they '[did] not know where she was killed' led me to believe they found a blood trail from the driveway leading to where she was 'placed' ... but looking at that pic, I see no drops that I could identify as blood.
One of the news videos from the CB scene show LE unloading lots of dive equipment items, (IIRC), right where you are seeing some of those scraps and markings.... so you might wanna take that into account.
ETA: Found the video showing LE unloading stuff at the place in del rio's picture
here.
While unsuccessful looking for the correct video, (King 5/NWCN ones aren't playing for me), I did find
this one from the AP, which describes the body as only
30 yards from the CB home, (at about 38 seconds into the video).
ETA: Measurements: (some I also mentioned in a previous post):
Google earth shows from closest corner, (SE corner), of garage to....
... start of heavy brush....................40 yards
... "high" RIVER water.......................66 yards
... where pond water enters river........67 yards
... river on the day MC was found.......77 yards
... duck blind area............................58 to 62 yards
... outlet of piped pond "water"...........34 yards
Leaves me to wonder how the AP got the 30 yard measurement. If body was moved 30 yards from closest section of driveway that would reach just below the outlet of piped pond "water".
Also, no matter where you start your measurement on the house, the "high" water mark of any river "water" is never within 60 yards.
To get these measurements I am using: (1) Google earth measurements, (which I think are fairly reliable), (2) a satellite image of the property from June 2006, (not sure how much more work was done after this point, i.e. if pond/pool water was piped farther down the hill) (3) my eyeballs and some guess work, (hard to tell where heavy brush begins, guessing on how low river water was based on news images from scene when body found).