Dendrite Butte is another popular rockhounding area of Central Oregon located near Congleton Hollow Rockhounding Site, 55 miles east of Prineville. Both sites are Limb Cast Collection Areas famous for limb casts with blue, pink, and green shades. Also, opalized and petrified wood can be found here.
Limb Casts are formed when quartz deposits replace the wood in the volcanic ash cavities. The hot ash caused the wood burns out, leaving empty tree-shaped cavities (mold). Over time, the cavities were filled with chalcedony and other minerals, forming beautiful clear, gray, green or pink crystals, often dendritic. Limb Casts have a shape of the wood.
The 540-acre Dendrite Butte is designated by BLM as a recreational rock and mineral collecting site, listed on the Central Oregon Rockhounding Map which is available for purchase.
Material can be obtained on the northern side of the road or on the left when you drive to the collecting area. The road is a boundary of the South Fork Wilderness Study Area on the right. Digging is not allowed on wilderness land.
There are two ways to attack here: hike searching around for float materials or dig with a shovel or pick.
Congleton Hollow Rockhounding Site is located nearby, but the shortcut is impossible because of private property at the northern side of the collecting area.
The road is rough, bumpy, and muddy when wet. Four-Wheel Drive is recommended.
Dendrite Butte Rockhounding Area | General Description
Open: Best time: May-October
Rocks & Minerals: Limb casts, petrified and opalized wood
Tools: Shovel, geology pick
Activities: Rockhounding, camping, and wildlife observing
Accommodations: Camping is allowed on BLM land
Distance from the parking: Vary
Road access: A high-clearance 4WD vehicle is recommended, the road can be inaccessible during wet weather
Day-use fees: None
Elevation: 4,450 ft (1,356 m)
Dendrite Butte is located:
- 55 miles southeast of Prineville
- 80 miles east of Bend
- 204 miles southeast of Salem.