Opal Butte: Hyalite Opal Rockhounding in Morrow County, Oregon

Permission requiredBest spot1 mineralMorrow County, OregonUpdated June 2026

4 photos

Mineral reported: 1
Elevation: 5,020 ft
Best months: March to October

Opal Butte is noted for hyalite and several gem opal varieties, including rainbow, contra luz, hydrophane, crystal, fire, and blue opal. That range, documented in gemological literature and Mindat locality records, makes the permission-required Morrow County site one of Oregon's more distinctive opal occurrences. Reported finds include hyalite opal. Below: coordinates, access notes, nearby spots, and trip-planning links.

Plan your visit

Permission required before collecting

County: Morrow County
State: Oregon
Coordinates: 45.04372, -119.61342

Get directions View on Google Maps

Coordinates are approximate. Confirm the exact ground in the RockHoundR app, where land overlays show which agency manages the area.

Land & collecting status

Permission required before collecting

Requires landowner or agency permission before any collecting. Do not enter without explicit authorization.

Public-land rules vary by agency, season, and field office. The RockHoundR app pulls live BLM, USFS, NPS, and tribal overlays so you can see exactly which agency manages the ground at this spot.

Best time to visit Opal Butte

33°J

40°F

48°M

55°A

63°M

71°J

83°J

83°A

73°S

57°O

42°N

32°D

Comfortable months (45 to 90°F highs)

Best months: March to October. Typical highs run 83°F in midsummer and 33°F in midwinter, with winter lows near 12°F.

Climate normals: NOAA 1991-2020 monthlies, MONUMENT 2 station (18 mi away), adjusted for elevation.

Geology at Opal Butte

This spot sits on John Day/Clarno Group, mapped as tuff, white, grayish yellow, very pale orange, pinkish gray, ash-flow tuff, tuffaceous sediment, and lapilli tuff that formed roughly 56 to 23 million years ago. Volcanic ground like this is where agate, jasper, and other chalcedony typically form, filling old gas pockets and fracture seams in the flow rock.

Mapped unit: John Day/Clarno Group
Age: 56–23 Ma (Eocene to Oligocene)
Rock types: tuff, white, grayish yellow, very pale orange, pinkish gray, ash-flow tuff, tuffaceous sediment, and lapilli tuff
Elevation: 5,020 ft

Geologic mapping via Macrostrat and the underlying state geological survey maps (CC BY 4.0). Bedrock at the surface can vary within a mapped unit.

Today's weather

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Sources & verification

Spot details combine the public RockHoundR location dataset, normalized mineral labels, agency land-status checks in the app, and community submissions. Coordinates are approximate until verified in the field.

State guidance last verified: April 1, 2026

BLM Oregon/Washington, Rockhounding & mineral material
Oregon Department of Geology and Mineral Industries (DOGAMI)
Oregon Parks and Recreation Department, beach collecting rules
Community submissions reviewed against published agency rules

Found at Opal Butte

Each name opens all spots that produce that material; the encyclopedia link opens the full ID and field guide.

Hyalite Opal Encyclopedia →

Nearby rockhounding spots

Other rockhounding spots within driving distance of Opal Butte.

General AreaMorrow County, Oregon · 20 mi awayNodules Filled With Opal
Wheeler High School Fossil BedsWheeler County, Oregon · 29 mi awayFossil
John Day RiverGrant County, Oregon · 38 mi awayFossil, Petrified Wood
John Day River & StreamsWasco County, Oregon · 43 mi awayFossilized Fern
John Day River at Cottonwood Canyon State ParkGilliam County, Oregon · 49 mi awayAgate, Jasper, Petrified Wood
AntelopeWasco County, Oregon · 56 mi awayAgate, Chalcedony, Geode
Lucky Strike MineCrook County, Oregon · 57 mi awayThunderegg
Whistler SpringCrook County, Oregon · 57 mi awayThunderegg

Across the state line from Opal Butte

Opal Butte is close enough to the Oregon border that the next-closest rockhounding spots are in a neighboring state. Worth knowing if you are already on the road.

Horse Heaven HillsBenton County, Washington · 76 mi awayOpalized Wood
MabtonYakima County, Washington · 79 mi awayPetrified Wood, Opalized Wood

Opal Butte FAQ

Where is Opal Butte?+

Opal Butte is in Morrow County, Oregon, at 45.04372, -119.61342.

What rocks and minerals can you find at Opal Butte?+

Opal Butte is reported to produce Hyalite Opal.

Is collecting allowed at Opal Butte?+

Permission required before collecting. Requires landowner or agency permission before any collecting. Do not enter without explicit authorization. Always confirm current rules with the managing agency before a trip.

What tools should I bring to Opal Butte?+

Most agate and jasper is surface float: bring a spray bottle, a pick or small shovel, and a sturdy bag. Wet stones show their banding and translucence.

When is the best time to visit Opal Butte?+

The most comfortable months at Opal Butte are March to October.

How do I get to Opal Butte?+

Open the directions link to navigate to 45.04372, -119.61342 in Google Maps. Some spots are remote, so check road conditions before driving out.