The drive from Pueblo to Wetmore takes you out of the high plains climate zone and into the low montane zone. This is seen by the effects of the increase in precipitation: the grasses and cacti give way to the junipers and pinons of the foothills.

This section of the Frontier Pathways Scenic & Historic Byway travels up Hardscrabble Canyon to McKenzie Junction. The canyon is narrow and very rugged here, with large granite outcroppings and lots of water flowing.

Over 150 years ago this area was populated by French traders, scrappy Americans and Mexican farmers and their families. In 1844 several Americans from El Pueblo established a Trading Post at San Buenaventura de los Tres Arrollos, a name changed a short while later to Hardscrabble. According the George Simpson, this was because of the "hard scrabbling to get in a crop" in the gravelly soil. In 1846, a dry year had most of Hardscrabble's residents packing. When John C. Fremont came through in 1848 he found the settlement at Hardscrabble almost completely deserted.

The granite that composes most of the Wet Mountains solidified some 1.7+ billion years ago, in the Pre-Cambrian era (essentially, before any life began on Planet Earth). It's the same age as the granite in the Blanca Massif. While most of this mountain range is Pre-Cambrian granite, there are a couple areas of Cambrian metamorphic rock (north and east of Lake DeWeese) and the rock deposited at the top of Greenhorn Mountain is only about 25 million years old and solidified about the same time as the Spanish Peaks and the Silver Mountain-Mt. Mestas group. The mining areas around Querida and Rosita are in rock about the same age as the top of Greenhorn (Oligocene/Middle Tertiary period).