MINERALS. CRYSTALS. GEMSTONES. FIND OUT MORE. Earthâs crust is made of rock, and rock is made of natural substances called MINERALS. There are three main types of rockâsedimentary, igneous, and metamorphic rock. Each type is produced in different ways.The oldest rocks on Earth were formed about 3.8 billion years ago.INERALS. CRYSTALS. GEMSTONES. FIND OUT MORE. Earthâs crust is made of rock, and rock is made of natural substances called MINERALS. There are three main types of rockâsedimentary, igneous, and metamorphic rock. Each type is produced in different ways.
Twisted Sisters: The Texas Hill Countryâs Most Famous Trio. This route connects the Twisted SistersâHill Country Ranch Roads 335, 336 and 337ânorthwest of San Antonio, Texas. Three Hill Country Ranch Roads, 335, 336 and 337, are known throughout Texas as the Twisted Sisters, and riders come from near and far to enjoy them. For me it is near, just a short ride from my home to the first Sister.
Have ridden the Sisters on three trips this spring. The ride from Kerrville on Hwy 16 to Medina and then west on 337 to Leakey was as much fun as the Sisters - and much more challenging. Take Hwy 39 to Hwy 83 from Kerrville for a nice ride to Leakey if you want to avoid the 1st gear, straight uphill switchbacks on 16.