First, add terrain for an area around South Boulder Peak by calling addCustomTerrain and specifying a DTED file. Name the terrain 'southboulderpeak'.

addCustomTerrain('southboulderpeak','n39_w106_3arc_v2.dt1')

Create a geographic globe. Specify the terrain by name, using the 'Terrain' argument of the geoglobe function. Preserve the terrain after plotting by calling the hold function. Then, plot the line. Tilt the view by holding Ctrl and dragging.

uif = uifigure;
g = geoglobe(uif,'Terrain','southboulderpeak');
hold(g,'on')

lat = [39.95384 39.95];
lon = [-105.29916 -105.3608];
hTerrain = [10 0];
geoplot3(g,lat,lon,hTerrain,'y','HeightReference','Terrain', ...
     'LineWidth',3)

Close the geographic globe and remove the custom terrain.

close(uif)
removeCustomTerrain('southboulderpeak')

The DTED data used in this example is courtesy of the US Geological Survey.