Malheur National Wildlife Refuge is a

National Wildlife Refuge National Wildlife Refuge System is a designation for certain protected areas of the United States managed by the United States Fish and Wildlife Service. The National Wildlife Refuge System is the system of public lands and waters set aside to c ...

located roughly south of the city of

Burns Burns may refer to: * Burn, an injury (plural) People: * Burns (surname), includes list of people and characters Business: * Burns London, a British guitar maker Places: ;In the United States * Burns, Colorado, unincorporated community in Eagle ...

in Oregon's Harney Basin. Administered by the United States Fish and Wildlife Service, the refuge area is roughly T-shaped with the southernmost base at Frenchglen, the northeast section at Malheur Lake and the northwest section at Harney Lake. The refuge was created in 1908 by order of President Theodore Roosevelt to protect habitat for diverse waterfowl and

migratory birds Bird migration is the regular seasonal movement, often north and south along a flyway, between breeding and wintering grounds. Many species of bird migrate. Migration carries high costs in predation and mortality, including from hunting by ...

, and grew to encompass of public lands. A popular site for birding, fishing, hunting and hiking, the refuge gained widespread attention in early 2016 after its headquarters complex was occupied by armed anti-government protesters.

History

Archaeological research within the Harney Basin region, including near Burns, Oregon, demonstrates that it likely was home to Native Americans for about the past 16,000 to 15,000 years. The first recognizable remains of seasonal prehistoric dwellings appear later in the Harney Basin at the Dunn Site about 5,500 BP. Around Malheur and Harney lakes, the presence of identifiable remains of numerous settlements and burials of the Boulder Village Period demonstrate that these lakes were heavily utilized by Paiute tribes for hunting and fishing as part of their seasonal nomadic round of the Harney Valley from before 3,000 BP up until historic contact with and settlement of the area by non-Native peoples.Aikens, C.M., T.J. Connolly, and D.L. Jenkins (2011) ''Oregon Archaeology.'' Oregon State University Press, Corvallis, Oregon. 512 pp. O'Grady, P.W. (2006
''Before Winter Comes: Archaeological Investigations of Settlement and Subsistence in Harney Valley, Harney County, Oregon.''
unpublished PhD dissertation, Department of Anthropology. University of Oregon, Eugene, Oregon. 541 pp. For example, the Malheur National Wildlife Refuge Headquarters lies within a major archaeological site that was once a settlement used by Paiute tribes seasonally for thousands of years until historic contact.Aikens, C.M., and R.L. Greenspan (1988
''Ancient Lakeside Culture in the Northern Great Basin: Malheur Lake, Oregon.''
Journal of California and Great Basin Anthropology. 10(1):32-61. The arrival of settlers in the region led to restrictions on the use of the land by the Paiute people who were eventually restricted to living in the

Malheur Indian Reservation The Malheur Indian Reservation was an American Indian reservation established for the Northern Paiute in eastern Oregon and northern Nevada from 1872 to 1879. The federal government discontinued the reservation after the Bannock War of 1878, ...

.''Malheur Indian Reservation.''The Oregon Historical Project
January 31, 2016 After it was established, the size of the Malheur Indian Reservation continued to shrink as small areas of it were repeatedly extracted from it and transferred to local settlers for their private use. The Paiute people were also denied the local fishing and hunting rights that were promised them.Whiting, B.B. (1950) ''Paiute Sorcery.'' Viking Fund Publications in Anthropology no. 15, 110 pp. New York. The Paiute people were forced to leave their Malheur Indian Reservation after joining the

Bannock people The Bannock tribe were originally Northern Paiute but are more culturally affiliated with the Northern Shoshone. They are in the Great Basin classification of Indigenous People. Their traditional lands include northern Nevada, southeastern Oreg ...

in Idaho in an uprising, the

Bannock War The Bannock War of 1878 was an armed conflict between the U.S. military and Bannock and Paiute warriors in Idaho and northeastern Oregon from June to August 1878. The Bannock totaled about 600 to 800 in 1870 because of other Shoshone peoples b ...

, in 1878, and were resettled in

Yakama Reservation The Yakama Indian Reservation (spelled Yakima until 1994) is a Native American reservation in Washington state of the federally recognized tribe known as the Confederated Tribes and Bands of the Yakama Nation. The tribe is made up of Klikitat, ...

, away in southeastern Washington. About 550 Paiute men, women, and children, of whom many had not engaged in any hostile action, traveled for nearly a month through the snow and over two mountain ranges. Even though supplies were in transit from the Malheur agency, the Paiute people were forced to leave Camp Harney under-equipped. As a result, five children, one woman, and an elderly man died along the way and were left unburied as they traveled. During the five years they spent on the Yakama Reservation, historian Sally Zanjani estimates that more than one-fifth of them died during their exile, mostly of malnourishment and disease. When they were allowed to leave the reservation in 1883, some of the Paiute people moved to either the

Warm Springs Reservation The Warm Springs Indian Reservation consists of in north-central Oregon, in the United States, and is governed by the Confederated Tribes of Warm Springs. Tribes Three tribes form the confederation: the Wasco, Tenino (Warm Springs) and P ...

or Nevada. Others returned to the Harney Basin and in 1972, acquired title to of land and created the

Burns Paiute Indian Reservation The Burns Paiute Tribe of the Burns Paiute Indian Colony of Oregon is a federally recognized tribe of Northern Paiute Indians in Harney County, Oregon, United States.''Report by W.V. Rinehart, 1879.''The Oregon Historical Project
January 31, 2016 After the removal of Paiute tribes, much of the region's land became public property. The region hosted large livestock operations while the area's water resources were altered by irrigation and drainage projects.

Devastation and study of bird life

The remarkable abundance and diversity of bird life within the pre-irrigation Malheur region was first described by

Charles Bendire Major Charles Emil Bendire (April 27, 1836 – February 4, 1897) was a United States Army soldier and noted ornithologist and oologist. The Bendire's thrasher is named for him. Early life Born Karl Emil Bender at König im Odenwald in the Gran ...

in the middle 1870s.Brewer, W.T.. (1877) ''Notes on Seventy-nine Species of Birds Observed in the Neighborhood of Camp Harney, Oregon, compiled from the correspondence of Captain Charles Bendire, 1st Cavalry, U. S. A.'' Proceedings Boston Society of Natural History. vol. 18, pp. 153-168.Bendire, C. (1878) ''Notes on Some of the Birds found In Southeastern Oregon, particularly in the Vicinity of Camp Harney, from November 1874, to January 1877.'' Proceedings Boston Society of Natural History. vol. 19, pp. 109-149, November, 1877. Beginning in the late 1880s, the area's bird populations were devastated by the actions of

plume hunters Plume hunting is the hunting of wild birds to harvest their feathers, especially the more decorative plumes which were sold for use as ornamentation, such as aigrettes in millinery. The movement against the plume trade in the United Kingdom wa ...

who harvested the showy feathers of Malheur's waterfowl for use as hat ornaments. In 1908, wildlife photographers William L. Finley and Herman Bohlman documented the area's unusual diversity of birds, as well as the detrimental impacts of plume hunting.Finley, W.L. (1908) ''Report of Wm. L. Finley n a trip to Malheur Lake in May, 1908' Bird-Lore. vol. X, no. 6, pp. 291-295, November–December, 1908. Finley used photographs to personally lobby

President Theodore Roosevelt Theodore Roosevelt Jr. ( ; October 27, 1858 – January 6, 1919), often referred to as Teddy or by his initials, T. R., was an American politician, statesman, soldier, conservationist, naturalist, historian, and writer who served as the 26t ...

for federal protection of the region.

Creation and expansion of the refuge

Malheur National Wildlife Refuge was created on August 18, 1908 by a proclamation from President Roosevelt, under a law which allowed the president to declare game preserves on federal public land. The refuge began as a parcel surrounding Malheur Lake, Harney Lake and Mud Lake, and was originally named the Malheur Lake Refuge. In the years that followed, the refuge grew to its current size of through federal purchases and acquisitions of surrounding lands. Of its current acreage, were acquired by purchase from various willing sellers; were acquired by condemnation; were acquired by purchase from a willing seller as part of the Blitzen Valley Project in 1935; were acquired in exchange for of refuge land; were acquired by direct donation; and were already existing public domain land. The creation and expansion of this refuge involved litigation, of which two lawsuits ended in favorable

Supreme Court A supreme court is the highest court within the hierarchy of courts in most legal jurisdictions. Other descriptions for such courts include court of last resort, apex court, and high (or final) court of appeal. Broadly speaking, the decisions of ...

decisions, that provide the legal foundation for its ownership and management by federal agencies.U.S. Fish and Wildlife Service (2013
''Chapter 1 Introduction and Background.''
i

U.S. Department of the Interior, Washington DC. Roads and other infrastructure were built by workers with the Civilian Conservation Corps during the

Great Depression The Great Depression (19291939) was an economic shock that impacted most countries across the world. It was a period of economic depression that became evident after a major fall in stock prices in the United States. The economic contagio ...

. While cattle grazing was permitted on some portions of the property after 1935, the prioritization of the needs of the refuge's wildlife led to reductions in the number of cattle allowed on the property starting in the 1970s. The number of cattle allowed to graze within the refuge remained at a steady level throughout the 1990s and 2000s. As the need for a comprehensive management plan for the refuge was realized, ranch operators became concerned about the possibility of further reductions in grazing allotments.

Recent history

Drafting of a new management plan began in 2008, and was a collaborative process involving varied stakeholders in the refuge's future, including ranch operators. The final plan, completed in 2013 and intended to inform refuge operations for the following 15 years, was accepted by environmentalists, refuge managers, cattle owners and the Paiute tribe as an agreeable compromise between potentially opposing interests in the land. Grazing was allowed to continue under the innovative plan, and is seen as a valuable tool in some areas to combat invasive plants that threaten the refuge's habitat quality; however, the extent of grazing may be reduced in specific areas if it is scientifically shown to be detrimental to the refuge's wildlife.

2016 occupation

From January 2 to February 11, 2016, the refuge's headquarters was seized by armed protesters related to the 2014 Bundy standoff. For most of the occupation, law enforcement allowed the occupiers to come and go at will. At the conclusion, most of the leaders were arrested, and one was killed while traveling away from the refuge when the group he was leading attempted to evade a police road block. The remaining occupiers either departed or surrendered peacefully. With respect to the refuge, they demanded that the federal government relinquish control so that, according to the occupiers, "the people can have their resources". Various stakeholders interested in the protection of the refuge, including the Portland Audubon Society and the

Burns Paiute Tribe The Burns Paiute Tribe of the Burns Paiute Indian Colony of Oregon is a federally recognized tribe of Northern Paiute Indians in Harney County, Oregon, United States.common carp The Eurasian carp or European carp (''Cyprinus carpio''), widely known as the common carp, is a widespread freshwater fish of eutrophic waters in lakes and large rivers in Europe and Asia.Fishbase''Cyprinus carpio'' Linnaeus, 1758/ref>Arkive The ...

, and protection of archaeological sites within the refuge. Concerns were also raised regarding the occupiers' handling of Burns Paiute artifacts stored at the refuge's headquarters, as well as direct impacts to the refuge and damage to an important archaeological site caused by road construction, destruction of fencing, and damage to a research field station.

Geography

Malheur Wildlife Refuge (Harney County, Oregon scenic images) (harDA0014)

The

Donner und Blitzen River The Donner und Blitzen River is a river on the eastern Oregon high desert that drains a relatively arid basin, the southern portion of Harney Basin, from roughly 20 to 80 miles (30 to 130 km) south-southeast of Burns including Malheur Nation ...

flows northward through the middle of the refuge, and is irrigated out to create a large artificial wetland, where once a natural wetland stood. The Donner und Blitzen River flows into Malheur Lake, which flows into Harney Lake forming a large

salt lake A salt lake or saline lake is a landlocked body of water that has a concentration of salts (typically sodium chloride) and other dissolved minerals significantly higher than most lakes (often defined as at least three grams of salt per litre). ...

. This open water brings thousands of migrating birds through the wildlife refuge every year as has happened for thousands of years before in the past. Including the extensive marshland, the total size of the refuge is . Exceptionally hot in the summer, and cold in the winter, the late spring and early fall are popular times to visit. Malheur National Wildlife Refuge is home to one of the most extensive

freshwater marsh A freshwater marsh is a non-tidal, non-forested marsh wetland that contains fresh water, and is continuously or frequently flooded. Freshwater marshes primarily consist of sedges, grasses, and emergent plants. Freshwater marshes are usually found ...

ecosystems in the western United States. These marshes lie in the desiccated lake bed of a Pleistocene age pluvial lake.U.S. Fish and Wildlife Service (2013
''Chapter 3 Physical Environment.''
i

U.S. Department of the Interior, Washington DC. Located along the southeast side of the Malheur National Wildlife Refuge is the

Diamond Craters The Diamond Craters is a monogenetic volcanic field about southeast of Burns, Oregon. The field consists of a area of basaltic lava flows, cinder cones, and maars. The reexamination of radiocarbon dates from older studies and interpretation of ...

volcanic field. It lies about southeast of the city of

. This monogenetic volcanic field consists of a area of basaltic lava flows,

cinder cone A cinder cone (or scoria cone) is a steep conical hill of loose pyroclastic fragments, such as volcanic clinkers, volcanic ash, or scoria that has been built around a volcanic vent. The pyroclastic fragments are formed by explosive eruptions o ...

s, and

maar A maar is a broad, low-relief volcanic crater caused by a phreatomagmatic eruption (an explosion which occurs when groundwater comes into contact with hot lava or magma). A maar characteristically fills with water to form a relatively shallow ...

s. A reexamination of old radiocarbon dates and interpretation of paleomagnetic data and new radiocarbon dates limits the eruption of volcanic vents in this volcanic field to the time period between 7320 and 7790 calendar years B.P.Sherrod, D.R., D.E. Champion, and J.P. McGeehin (2012) ''Age and duration of volcanic activity at Diamond Craters, southeastern Oregon.'' Journal of Volcanology and Geothermal Research. 247–248:108–114 North of Diamond Craters, a late Pleistocene basaltic lava flow, called the ''Voltage Flow'', forms a high-standing subdued ridge that marks the eastern boundary of the pluvial lake basin that is now occupied by Malheur, Mud, and Harney lakes. The Voltage Flow was erupted about 1.9 million years ago from several volcanic vents located north of Diamond Craters. At that time, the Voltage Flow created the pluvial lake basin that the Malheur National Wildlife Refuge currently occupies by filling the paleovalley of and damming the prehistoric course of Malheur River at that time.Milliard, J.B.. (2010
''Two-stage opening of the northwestern Basin and Range near Harney Basin, Oregon, USA: structural, sedimentological and volcanic constraints.''
unpublished Masters thesis, College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, Oregon. 80 pp.

Wildlife

Wildlife in the area includes as many as 320 species of

birds Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweigh ...

and 58 species of mammals in desert, grassland, marsh and

rimrock Rimrock is the sheer rock wall at the upper edge of a plateau, canyon, or geological uplift. It may refer to either the rock formation or to the rock itself. Rimrock may be composed of almost any stone—basalt, gneiss, granite, sandstone, et ...

habitats. Malheur is one of the most productive waterfowl breeding areas in the United States and is an essential migration stop for hundreds of thousands of birds following the Pacific Flyway.Johnson, D.M., R.R. Petersen, D.R. Lycan, J.W. Sweet, M.E. Neuhaus, and A.L. Schaedel (1985). ''Atlas of Oregon Lakes.'' Corvallis: Oregon State University Press. pp. 100-101. . Among the migrating birds that depend upon this refuge as a migration stop for rest and foraging are northern pintail and tundra swan, lesser and greater sandhill crane, snow goose and Ross’ goose. Ducks, grebes, pelicans and trumpeter swans are drawn to the numerous ponds, marshes and lakes. Deer, antelopes, ducks, pheasants, thrashers and quails can be found in the upland areas in sagebrush,

greasewood Greasewood is a common name shared by several plants: * ''Adenostoma fasciculatum'' is a plant with white flowers that is native to Oregon, Nevada, California, and northern Baja California. This shrub is one of the most widespread plants of the ...

and wild rye. The lakes within the Malheur National Wildlife Refuge are important and irreplaceable foraging areas for migrating waterfowl, waterbirds, and

shorebirds 245px, A flock of Dunlins and Red knots">Red_knot.html" ;"title="Dunlins and Red knot">Dunlins and Red knots Waders or shorebirds are birds of the order Charadriiformes commonly found wikt:wade#Etymology 1, wading along shorelines and mudflat ...

and nesting habitat for colonial nesting waterbirds and diving ducks. When

sago pondweed ''Stuckenia pectinata'' (Synonym (taxonomy), syn. ''Potamogeton pectinatus''), commonly called sago pondweed or fennel pondweed, and sometimes called ribbon weed, is a Cosmopolitan distribution, cosmopolitan water plant species that grows in fres ...

is abundant in the lakes, it supports an abundance of canvasbacks, tundra swan, and many other dabbling and diving ducks in large numbers. When environmental conditions are favorable, very high numbers of nesting colonial birds, including

white-faced ibis The white-faced ibis (''Plegadis chihi'') is a wading bird in the ibis family, Threskiornithidae. This species breeds colonially in marshes, usually nesting in bushes or low trees. Its breeding range extends from the western United States south ...

;

American white pelican The American white pelican (''Pelecanus erythrorhynchos'') is a large aquatic soaring bird from the order Pelecaniformes. It breeds in interior North America, moving south and to the coasts, as far as Central America and South America, in winte ...

; great and

snowy egret The snowy egret (''Egretta thula'') is a small white heron. The genus name comes from Provençal French for the little egret, , which is a diminutive of , 'heron'. The species name ''thula'' is the Araucano term for the black-necked swan, app ...

heron The herons are long-legged, long-necked, freshwater and coastal birds in the family Ardeidae, with 72 recognised species, some of which are referred to as egrets or bitterns rather than herons. Members of the genera ''Botaurus'' and ''Ixobrychus ...

s; Franklin's, California, and ring-billed gulls;

Caspian Caspian can refer to: *The Caspian Sea *The Caspian Depression, surrounding the northern part of the Caspian Sea *The Caspians, the ancient people living near the Caspian Sea *Caspian languages, collection of languages and dialects of Caspian peopl ...

and Forster's terns; and western, Clark's, and eared

grebes Grebes () are aquatic diving birds in the order (biology), order Podicipediformes . Grebes are widely distributed freshwater birds, with some species also found in sea, marine habitats during Bird migration, migration and winter. Some flightless ...

, use the lake for nesting. Under favorable environmental conditions, the total number of nesting colonial waterbird nests have exceeded 10,000. When natural fluctuating water cycles expose mudflats within these lakes, migrant shorebirds use the lakes extensively. In addition, the expansive open water within Malheur Lake provides security for

molting In biology, moulting (British English), or molting (American English), also known as sloughing, shedding, or in many invertebrates, ecdysis, is the manner in which an animal routinely casts off a part of its body (often, but not always, an outer ...

geese and ducks that exceeded 10,000 in number from

predators Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill the ...

. When Harney Lake is full, extensive beds of widgeongrass support well over 300,000 migrating ducks.U.S Fish and Wildlife Service (2013
''Chapter 4 Biological Environment.''
i

U.S. Department of the Interior, Washington DC. Faunal remains found in local archaeological sites demonstrate that the lakes within the Malheur National Wildlife Refuge were just as important as foraging and nesting habitat for innumerable migrating and nesting birds for thousands of years into the prehistoric past as they are today. In addition to birds, these lakes once supported large numbers of muskrats, beaver, and mink. Redband trout, which is a group of three recognized subspecies of

rainbow trout The rainbow trout (''Oncorhynchus mykiss'') is a species of trout native to cold-water tributaries of the Pacific Ocean in Asia and North America. The steelhead (sometimes called "steelhead trout") is an anadromous (sea-run) form of the coasta ...

(''Oncorhynchus mykiss''), are found in the tributaries and endorheic basins in the western United States. The Harney Basin, in which lie Malheur and Harney lakes, is the largest of these Oregon desert basins and contains the most diverse and greatest amount of redband trout habitat. This habitat includes Harney and Malheur lakes along with the Donner und Blitzen River, Silver Creek, and the Silvies River. Within the Harney Basin, the redband trout occur as ten distinct populations. One each occurs in Donner und Blitzen River, Silver Creek, and the Silvies River. Six of these redband trout populations exist as small communities in isolated creeks that dissipate onto the valley floor in the northeast and southeast regions of the basin. Finally, the tenth small population occupies McCoy Creek and have a one-way connection to the Donner und Blitzen River. Together with adjacent acreage owned by the

Bureau of Land Management The Bureau of Land Management (BLM) is an agency within the United States Department of the Interior responsible for administering federal lands. Headquartered in Washington DC, and with oversight over , it governs one eighth of the country's la ...

, Malheur National Wildlife Refuge in part provides critical protection to these redband trout populations. They are the survivors of the desiccation and disappearance of the last pluvial lake that filled the Harney Basin during the

Last Glacial Maximum The Last Glacial Maximum (LGM), also referred to as the Late Glacial Maximum, was the most recent time during the Last Glacial Period that ice sheets were at their greatest extent. Ice sheets covered much of Northern North America, Northern Eur ...

.Bisson, P.A., and C.E. Bond (1971) ''Origin and Distribution of the Fishes of Harney Basin, Oregon.'' Copeia. 1971(2): 268-281.Behnke, R.J., and J.R. Tomelleri. (2002). ''Rainbow and Redband Trout''. Trout and Salmon of North America. The Free Press. pp. 65–122. . Refuge officials have been actively managing an overabundance of

common carp The Eurasian carp or European carp (''Cyprinus carpio''), widely known as the common carp, is a widespread freshwater fish of eutrophic waters in lakes and large rivers in Europe and Asia.Fishbase''Cyprinus carpio'' Linnaeus, 1758/ref>Arkive The ...

(''Cyprinus carpio'') in the refuge since at least the 1970s. The invasive fish species was likely introduced to the refuge's waterways prior to the 1920s as a food source, and has been recognized as an ecological threat to the region since the 1950s. Carp are aggressive feeders that have reduced food availability and diminished habitat quality for the bird species that utilize the refuge's marshes and lakes. In 2014, a $35,000 contract to capture and remove carp was awarded to a fishing crew that specializes in the removal of invasive fish species.

Fossils

Fossilized bones have been found within and adjacent to Malheur National Wildlife Refuge. Within Malheur National Wildlife Refuge, paleontologists have found the fossil bones of an unidentified camel-like species in Pleistocene volcanic ash deposits. This fossil site has the potential of yielding additional fossil animals and plants. Such fossils are of a regional importance as fossils from this geologic time period have not been found elsewhere in eastern Oregon. In addition, unnamed

Neogene The Neogene ( ), informally Upper Tertiary or Late Tertiary, is a geologic period and system that spans 20.45 million years from the end of the Paleogene Period million years ago ( Mya) to the beginning of the present Quaternary Period Mya. ...

volcaniclastic and sedimentary strata have also yielded vertebrate fossils. They were collected from these strata in areas south of Harney Lake. These fossils bones indicate that the strata in which they occur date to both the

Barstovian The Barstovian North American Stage on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages chronology (NALMA), typically set from 16,300,000 to 13,600,000 years BP, a period of . It is usua ...

(Middle Miocene) and Clarendonian (Lower Miocene) stages.Walker, G.W. (1979
''Revisions to the Cenozoic stratigraphy of Harney Basin, southeastern Oregon.''
Bulletin no. 1475. U.S. Geological Survey, Reston, Virginia. Finally, Late Pleistocene, 22,000 year-old, fossil salmon bones have been reported being found in prehistoric gravel ''spawning'' beds that were uncovered near the connection between Malheur and Mud lakes. These fossils have been interpreted as indicating that the lake level of this prehistoric pluvial lake was high enough at this time that it was connected to and discharged directly into the Malheur River.

References

External links

U.S. Fish and Wildlife Service: Malheur National Wildlife RefugeThe Story Behind Malheur National Wildlife Refuge
Bob Sallinger.
Harney Basin Wetlands Initiative
High Desert Partnership.
Paiute HistoryWelcome to the Burns Paiute Tribe
Burns, Oregon. {{authority control 1908 establishments in Oregon Civilian Conservation Corps in Oregon Landforms of Harney County, Oregon Bundy standoff National Wildlife Refuges in Oregon Protected areas established in 1908 Protected areas of Harney County, Oregon Wetlands of Oregon