6. Unionpeak-Castlecrest (mountain hemlock)
Percentage of park: 7 percent
Location in park: Along the northern, eastern, and southern flanks of the caldera rim
Drainage class: Somewhat excessively drained
Slope range: 0 to 35 percent
Elevation: 5,000 to 7,000 feet
Average annual precipitation: 50 to 70 inches
Average annual air temperature: 38 to 42 degrees F
Frost-free period: 0 to 50 days
Minor components: 10 percent Sunnotch soils and 5 percent Rock outcrop
Present vegetation: Mountain hemlock and lodgepole pine
Unionpeak soils
Depth class: Moderately deep to a duripan
Permeability: Rapid throughout the solum and moderately rapid in the weakly cemented duripan
Position on landscape: Ashflows
Parent material: Pumice, ash, andesite, and dacite
Surface texture: Ashy sandy loam
Subsoil texture: Gravelly ashy loamy sand
Castlecrest soils
Depth class: Very deep
Permeability: Rapid
Position on landscape: Mountain flanks and mountainsides
Parent material: Pumice and ash
Surface and subsoil texture: Paragravelly ashy loamy sand
Substratum texture: Ashy coarse sand and ashy sand
