We called them horny roads as kids, not sure which species this one is though.
Beavertail Cactus in Joshua Tree National Park
Sighted at Cottonwood Springs, Joshua Tree National Park
Sighted at CottonWood Visitor Center - Joshua Tree National Park
Sighted on the Botanic Trail at the Cottonwood Visitors Center of Joshua Tree National Monument
Desert Holly located in Golden Canyon, Death Valley NP
sighted at Ash Meadows NWR - and so I think it is a Nevada Side-Blotched Lizard