GPS'ing for elevation

[Maple Hunter]

If the GPS can accurately map the trees, is there a way of overlaying the tree locations on a USGS map?

Yes, you can do that with nearly any basic Topo software and easily with ArcMap (ArcGIS). However, I wouldn't trust the contour intervals completely, as they're not always perfect either. Has anyone tried an altimeter? Some are fairly accurate. I know one of my GPS units has one built in, but I've never messed with it much to know it's accuracy.

[The Sweet Spot]

Thanks Maple Hunter, I'm not the only one to notice this. The usgs shows my lines very different than they are.

[theschwarz1]

Many states and/or counties have flown LiDAR and have generated very accurate contours and hillshades. Look up your state or county's GIS daa. If you want free GIS Software I can help you with that.

[theschwarz1]

If the GPS can accurately map the trees, is there a way of overlaying the tree locations on a USGS map?

YEs there is. If you want I can help you create a very nice map with your GPS points and showing accurate elevation.

[maple flats]

I believe topo maps are drawn from areal photos. As such, lines are drawn thru a picture full of trees. Can't be 100%, but the get fairly close.

[maple man]

Best way to get most out of your elevation is run your wire. Then start at the releaser go to first tree it touches we made a two foot level with hook on one end .and 2/3/4/5 % hookes on the other end . Then work your way up the line in betewn tree start at 2% if geting to low go back and start over. When you have set right put nail in tree to hold wire and works as good referance point for future if tree takes line down. I do now side tying . If tree falls on line I can have back up level in now time.