Zn, Hg) veins and shear zones occur in the 74 Ma (million years old) quartz diorite, in small amounts in the schist and in the mafic unit, but not in the 67Ma quartz monzonite, and in only one instance in the Tertiary sediments. The gold occurrences in the schist, mafic unit, and sediments have much higher silver contents than the deposits in the quartz diorite. Most of the mineral deposits are close to the quartz diorite-schist contact. The Castle Mountain Fault is a major tectonic feature. It strikes ENE and passes a few miles south of Hatcher Pass. It can be clearly seen crossing the Hatcher Pass road where concrete barriers and fencing protect the road from rockfall of the "incompetent" rocks on the fault trace. Studies show that magnitude 7 earthquakes can be expected to occur on this fault with approximately a 700-year recurrence interval. The last big earthquake was probably 650 years ago. Recreational Activities Most of the pass is inside the Hatcher Pass East Special Management Area, which encompasses of wilderness. Summit Lake State Recreation Site is a small alpine park with a shallow cirque lake and excellent views. The park is a favorite launch site for paragliders. Activities that can be enjoyed in the Hatcher Pass area include Nordic skiing, downhill skiing, mountain climbing, white water kayaking, rock climbing, mountain biking, paragliding, berry picking, gold mining, hiking, kite-flying, snowboarding, wildlife viewing and back country camping. Hatcher Pass Road is a good paved biking trail until Mile 17, where the road changes to gravel. Mountain Biking The Gold Mint Trail provides miles of technical, rocky, gently-climbing mountain bike riding alongside the Little Susitna River. The "16-mile trail" is a steep downhill, 2-mile long (3 km) bike trail with of drop that was built in 2013, in between switchbacks of the Hatcher Pass road, starting at mile 16 of the Hatcher Pass Road. At Government Peak Recreational Area, a few miles (several km) south of Hatcher Pass, there are in three loops of singletrack, bermed, flow-style bike trails. References External links Landforms of Matanuska-Susitna Borough, Alaska Mountain passes of Alaska Ski areas and resorts in Alaska Tourist attractions in Matanuska-Susitna Borough, Alaska