Site Details

descriptions and directions

Cottonwood Marsh photo by Peter Burke

South Republican SWA - Yuma County
Aliases: Foster's Grove Campground, Wagon Wheel Campground, Bonny Lake State Park
Ownership: None Listed
Description: Together with the adjacent Hale Area (q.v.), this former large reservoir and adjacent riparian woodland reign supreme among the central plains migrant traps. Even with the not insignificant attention it gets, South Republican SWA(fee area) is among the most underbirded locations in Colorado, since most Colorado birders concentrate on either the northeast or southeast parts of the state in spring and fall. An enormous and amazing list of rarities has been seen at Bonny Reservoir, including things like Yellow-crowned Night-Heron, Groove-billed Ani, and practically every rare eastern passerine that has occurred in Colorado. Between the former reservoir, woodland, and some (relatively) high-quality prairie, almost anything could show up here.

The woods around the reservoir can be good for migrants, though sometimes Bonny suffers from having too much habitat. Generally, the more limited trees on the northern side of the lake concentrate the birds somewhat better, but the south can be good too. The best area on the north side is the large hedgerows and cottonwood groves by the Foster's Grove Campground, and the best area on the south side is along the aforementioned road that accesses the southwestern part of the reservoir. In addition to migrants, the woods around Bonny can also be good for a number of uncommon breeding species, such as Eastern Screech-Owl (common, but nocturnal), Baltimore Oriole (often fairly easy), Bell's Vireo (ditto), Field Sparrow (a little harder), Red-bellied Woodpecker, Northern Cardinal (sometimes hard to find here), and Eastern Bluebird (can vary from quite common to uncommon). In winter, various isolated hedgerows, especially those along CR 3 about a mile from US 385 and one near the Wagon Wheel Campground, can hold sparrows including Harris', White-throated, and others, and an occasional Long-eared and maybe even Short-eared or Saw-whet Owl. It may be worth checking these areas out for migrants as well. The trees along the river below the dam are also worth birding.

In summer Cassin's Sparrows breed in areas around the reservoir with lots of Yucca. During the winter it is often easy to find Lapland Longspurs in flocks of Horned Larks that abound on the nearby prairie. The dam manager's residence just north of the dam has a large collection of hedgerows that sports the occasional (albeit hard to find) wintering Saw-whet Owl. There is also a productive hedgerow just below the DOW bunkhouse that can at times also hold this tiny owl. Be sure to also bird the large cattail marshes just below the dam, where you may find Marsh Wren, Virginia Rail, and Sora, sometimes even in the winter. Once, a Woodcock was heard here. Other large cattail marshes can be found around the western and southwestern edges of the reservoir.

Habitat: Lake/Pond/Reservoir, Lowland Riparian, Marsh, Hedgerow/Shelterbelt, Grassland/Prairie, Yucca
Directions: South Republican SWA is just east of US 385 about 22 miles north of Burlington. Two entrance roads head east from US 385, one just south of the Republican River and the other just north. The northern access road (CR 3) heads east from US 385 to Foster Grove Campground, then winds a long distance around the north side of the reservoir to the dam road just north of the dam. The southern road (CR 2) heads straight east for a little over a mile before turning south to cross Landsman Creek. Where CR 2 bends south, an old access road, now blocked off, heads east to one of the best marshes at the SWA--you can't drive to it but it's an easy walk. Following CR 2 south across the creek and back to the east, you will see the unmarked dirt access road to the southwest part of the reservoir heading off to the left. Past this is the Wagon Wheel Campground and subsequently the south end of the dam.
Other Wildlife:
Other Attractions:

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Latest South Republican SWA Sightings from eBird


CBRC Records from South Republican SWA

SpeciesAccession No.Date(s)
American Black Duck1952-00110/22/1952
Groove-billed AniN-26-7210/3/1976
Groove-billed Ani1982-0049/17/1982
Black-billed Cuckoo26-89-255/14/1989
Black-billed Cuckoo2005-064 6/6/2005 - 7/9/2005
Hudsonian Godwit2000-0315/13/2000
Ruddy Turnstone2002-1215/20/2001
Pomarine Jaeger2001-15510/8/2000
Short-billed Gull2006-176 12/2/2001
Neotropic Cormorant2005-024 4/19/2005 - 5/16/2005
Least Bittern5-73-815/12/1973
Yellow-crowned Night-Heron5-96-65/19/1996
Yellow-crowned Night-Heron2006-120 9/4/2006
Swallow-tailed Kite10-85-165/13/1984
Red-shouldered Hawk10-76-222/15/1976
Red-shouldered Hawk10-76-475/5/1976
Red-shouldered Hawk2005-085 9/4/2005
Williamson's Sapsucker2020-040 23 Nov 2020
Yellow-bellied Sapsucker2003-085 
Scissor-tailed Flycatcher2012-029 5/14/2011
Yellow-throated Vireo51-72-384/24/1971 - 4/25/1971
Yellow-throated Vireo51-96-675/17/1996
Blue-headed Vireo2003-0699/7/2003
Philadelphia Vireo51-90-475/20/1990
Philadelphia Vireo2005-087 9/4/2006
Sedge Wren42-76-395/6/1976
Gray-cheeked Thrush44-75-465/11/1975
Gray-cheeked Thrush44-77-255/14/1977 - 5/15/1977
Gray-cheeked Thrush2013-279 05/11/1996
Wood Thrush44-87-585/17/1987
Wood Thrush2002-0605/19/2002
Sprague's Pipit2010-130 10/10/2010
Purple Finch56-77-101/22/1977 - 1/29/1977
Purple Finch56-82-441/3/1981
Purple Finch2008-008 1/27/2008 - 3/1/2008
Purple Finch2008-009 2/2/2008
Purple Finch2012-098 12/16/2011
Smith's Longspur2006-137 9/30/2006
Fox Sparrow (Red)2003-08411/14/2003
Fox Sparrow (Red)2005-146 12/23/2005
Fox Sparrow (Red)2007-069 10/13/2007
Eastern Towhee2005-145 12/22/2005 - 12/23/2005
Eastern Meadowlark2019-056 12 May 2019*
Worm-eating Warbler52-90-625/15/1990
Worm-eating Warbler52-94-755/14/1994
Worm-eating Warbler52-96-825/17/1996
Louisiana Waterthrush52-77-235/14/1977
Golden-winged Warbler52-85-24 5/12/1985
Blue-winged Warbler52-74-844/24/1971
Blue-winged Warbler52-96-725/10/1996
Prothonotary Warbler52-74-615/11/1974 - 5/12/1974
Prothonotary Warbler52-75-425/11/1975
Prothonotary Warbler52-93-165/16/1993
Mourning Warbler52-86-215/25/1986
Cape May Warbler2007-118 5/21/2007
Cape May Warbler2013-196 05/21/2013
Blackburnian Warbler52-74-855/18/1974
Blackburnian Warbler52-83-475/18/1983
Blackburnian Warbler2002-0615/19/2002
Pine Warbler52-78-515/14/1978
Pine Warbler2005-080 8/6/2005
Yellow-throated Warbler52-77-245/15/1977
Yellow-throated Warbler2009-031 5/11/2009
Prairie Warbler52-76-715/15/1976
Prairie Warbler1997-0916/1/1997
Prairie Warbler2003-1385/6/2003
Canada Warbler52-89-495/21/1989
Canada Warbler52-89-519/2/1989
Canada Warbler52-94-829/3/1994
Hepatic Tanager55-82-225/15/1982
Painted Bunting56-91-765/12/1991