Google Earth KML clampToGround allows subterranean lines - kml

Question

I am creating a Google Earth KML, and having trouble. My LineString won't stay above ground. I'm using clampToGround as instructed in the documentation, I think.
Why doesn't clampToGround keep the LineString above the ground here? If I'm reading the documentation right, it really should stay above the ground. I tried to work around it by going relativeToGround and giving it a little altitude, but that didn't work either. I just want to make sure the line is visible above ground for its whole length.
Salient portions of the KML:
<Placemark>
<name>Untitled Path</name>
<styleUrl>#m_ylw-pushpin</styleUrl>
<LineString>
<extrude>1</extrude>
<tessellate>1</tessellate>
<altitudeMode>clampToGround</altitudeMode>
<coordinates>
86.66797376467392,48.79933074280933,100 87.52400441880934,49.14303840409646,100
</coordinates>
</LineString>
</Placemark>
<Placemark>
<name>Untitled Path2</name>
<styleUrl>#m_ylw-pushpin</styleUrl>
<LineString>
<extrude>1</extrude>
<tessellate>1</tessellate>
<altitudeMode>clampToGround</altitudeMode>
<coordinates>
86.66797376467392,48.81933074280933,10 87.52400441880934,49.15303840409646,10
</coordinates>
</LineString>
</Placemark>
<Placemark>
<name>Untitled Path3</name>
<styleUrl>#m_ylw-pushpin</styleUrl>
<LineString>
<extrude>1</extrude>
<tessellate>1</tessellate>
<altitudeMode>relativeToGround</altitudeMode>
<coordinates>
86.66797376467392,48.91933074280933,10 87.52400441880934,49.25303840409646,10
</coordinates>
</LineString>
</Placemark>
The more I zoom in, the more gets occluded but the ground. How do I stop this?
I can still cause this to happen, even if drawing when very zoomed in:
Here's the KML:
<?xml version="1.0" encoding="UTF-8"?>
<kml xmlns="http://www.opengis.net/kml/2.2" xmlns:gx="http://www.google.com/kml/ext/2.2" xmlns:kml="http://www.opengis.net/kml/2.2" xmlns:atom="http://www.w3.org/2005/Atom">
<Document>
<name>aaaa.kml</name>
<Style id="s_ylw-pushpin_hl">
<IconStyle>
<scale>1.3</scale>
<Icon>
<href>http://maps.google.com/mapfiles/kml/pushpin/ylw-pushpin.png</href>
</Icon>
<hotSpot x="20" y="2" xunits="pixels" yunits="pixels"/>
</IconStyle>
</Style>
<Style id="s_ylw-pushpin">
<IconStyle>
<scale>1.1</scale>
<Icon>
<href>http://maps.google.com/mapfiles/kml/pushpin/ylw-pushpin.png</href>
</Icon>
<hotSpot x="20" y="2" xunits="pixels" yunits="pixels"/>
</IconStyle>
</Style>
<StyleMap id="m_ylw-pushpin">
<Pair>
<key>normal</key>
<styleUrl>#s_ylw-pushpin</styleUrl>
</Pair>
<Pair>
<key>highlight</key>
<styleUrl>#s_ylw-pushpin_hl</styleUrl>
</Pair>
</StyleMap>
<Placemark>
<name>Untitled Path</name>
<styleUrl>#m_ylw-pushpin</styleUrl>
<LineString>
<tessellate>1</tessellate>
<coordinates>
-110.8533929259622,43.78725268338503,0 -110.8487894073726,43.78768726798314,0
</coordinates>
</LineString>
</Placemark>
</Document>
</kml>