Whether it’s the roar of a rushing waterfall, the glimmer of gold in a stream, or a gentle breeze of fresh air, nature has a million gifts for humanity to behold. One such naturally occurring wonder is obsidian, a natural glass that has been used throughout the entirety of human history. Obsidian is formed when molten volcanic material cools rapidly with minimal crystallization.
Most obsidian is deep black or blackish green in hue, but it actually comes in a shocking variety of colors. Today, we explore this interesting mineral and where it can be found in Central Oregon.
The World’s Largest Obsidian Deposits
Obsidian is an extrusive igneous rock, which means it is formed from magma that erupted out of a volcano. This means that with volcanoes in their immediate vicinity are great spots for hopeful collectors. Oregon’s very own Glass Buttes are one such example. Roughly 5 million years old, they are home to one of the largest obsidian deposits in the world.
Located in the northeast corner of Lake County between Bend and Burns, these two large volcanic peaks tower over the desert plain. The highest peak is called Main Glass Butte, while the second is known as Little Glass Butte. Most of the obsidian occurs around these two peaks, but the hills and plains adjacent to them also contain a plentiful amount.
Obsidian hunting begins off of milepost 77 of Highway 20. Those coming from Bend should expect to travel around 70 miles southeast, while those from Burns around 50 miles west. The site itself is managed by the Bureau of Land Management, with 36 square miles of free-use area for the public to readily engage in rock collection and camping. There are no permits required to begin your adventure, but the Federal Government limits individual collection at 250 pounds of obsidian per year.
Because the area is fairly remote and rugged, a four-wheel drive vehicle is recommended. One should also have a spare tire and patch kit just in case, since obsidian shards cover the road and can be very sharp at times. Near milepost 77, there is a signpost that says “Obsidian Road” that tells you where to turn to head towards the free-use area. The dirt road is fairly well-defined and leads to the parking area after a short drive. You will also pass a flat camping area on the left of this road.
Lots of Obsidian, but No Services!
Primitive camping is permitted in the public area so one can expect to see a tent or two, but there are no facilities for toilets, garbage services and the like. Pack it in, pack it out! The nearby Chickahominy Reservoir does have some RV areas for those interested in stopping over.
Continuing along the gravel road towards Little Glass Butte, one can find gold sheen and silver sheen obsidian in the area before Musser Pond. Red-fire, rainbow and lace obsidian can be found adjacent to this, closer to the fence lined area southeast of the campsite. Some areas contain obsidian in such a plentiful amount that it is literally strewn on the ground ready to be picked up and brought home!
Following the gravel road to the west will take you closer to Main Glass Butte, where black and banded types can be found. The sheer diversity of obsidian in the Glass Buttes is a unique characteristic, and discovering the different varieties is all part of the rockhounding fun.
Maps are available in some rock shops in Bend and Pineville for those looking for specific direction from the locals.
Apart from the variants mentioned, one can also find mahogany (dark streaks that resemble wood), leopard (spotted), spider web, aurora borealis and even snowflake types of obsidian here.
Because obsidian is a type of glass, it breaks off extremely sharp. In fact, many native American cultures used this to make arrowheads, spears, cutting tools and even writing implements. Adventurers intending to explore the digging sites should have the tools to handle it accordingly. Hammers, picks, and goggles will prove useful, while buckets and thick cloth to layer in between each specimen will also help avoid breakage and chipping along the trek. Another useful recommendation is to wear closed-toe shoes or boots and bring a pair of thick gloves to avoid injury.
Lastly, the best time to venture out into the Buttes is towards late spring or fall, since the summer heat can sometimes prove intolerable and the rains and cold weather make the dirt roads difficult to navigate. For those heading to the Glass Buttes, be prepared to pack weather-appropriate gear, water and an enthusiastic mindset. As Oregon’s obsidian-laden gift that keeps on giving, the area will surely welcome avid rockhounds for years to come.