The Pacific Group has four subspecies:

• browningi is mostly resident from coastal sw British Columbia to west-central Washington; apparently some movement southwards in northernmost populations to sw Washington.
• paludicola is apparently resident from sw Washington to west-central Oregon. Pyle (1997) and older texts considered paludicola to be the coastal resident race all the way to San Diego, California, but Unitt et al. (1996) found no specimens of paludicola south of Lincoln Co., Oregon, nor did they report any evidence of migration.
• aestuarinus has an extensive but patchy range along the Pacific coast from s Oregon to Ventura Co., California, and eastward through the San Francisco Bay area and Central Valley, and southeast through the California deserts to the Salton Sea and Colorado River, with local breeding occurrence northwards into s Nevada and in Death Valley NP, California (per Unitt et al. 1996). Pyle (1997) and other texts had restricted aestuarinus to just the Central Valley and had recognized a desert race called 'deserticola' in south-eastern California and along the Colorado River. Unitt et al. (1996) merged 'deserticola' into aestuarinus, finding that the subspecies was only diagnosable at the sites at which it was originally named, but that intergradation between them was complete. Unitt et al. (1996) found little evidence of migration in aestuarinus and although there is some short-distance post-juvenal dispersing locally, they considered the subspecies to be resident. Pyle (1997) had thought there was some migration from the Central Valley to the coast. There is certainly some movement because Marsh Wrens appear throughout much of California in fall and winter at locations at which they do not breed.
• clarkae is resident in coastal southern California from Los Angeles Co. to San Diego Co., and inland to w Riverside Co. This subspecies was named by Unitt et al. (1996) and was not referenced at all in Pyle (1997), who considered it a part of paludicola.

The Interior West Group has three subspecies:

• pulverius from c British Columbia and south across much of the Great Basin, south to eastern California and Nevada, and including western Montana; winters to sw U.S., w Texas.
• plesius from se Idaho and w Wyoming through Utah, Colorado, and western Nebraska; winters from Kansas to Texas.
• laingi has a large range in central Canada east of the Rockies and south to ne Montana, much of North Dakota, and to c South Dakota; winters to New Mexico, Texas. This subspecies apparently intergrade with "eastern" Marsh Wrens in a broad swathe in the central prairies (as detailed on the previous page).

On range, these are pulverius, which is a medium large subspecies whose back in mostly "pale brown with little or no rufous," and with "pale brownish" flanks (Pyle 1997). Even though both of these photos are of somewhat worn birds in spring (particularly the photo from May), it is apparent that these are rather drab and plain brown birds when compared to populations on the east or west coast of North America.

photo (far left) 24 May 2009 Sanger Lake, Okanogan Co., WA © Dennis Paulson

photo (near left) 3 Apr 2011 near Burns, Harney Co., OR © Netta Smith

On range, these are plesius, from Utah and Colorado, and both photos are rather late in the season so the birds are worn. They look large, pale, and brown. Pyle (1997) states that fresh birds have a "rufous tinge" to rump, perhaps still slightly present in the Colorado photo.

photo (far left) 16 June 2001 Bear River NWR, UT © Greg W. Lasley

photo (near left) 19 May 2004 Weld Co., CO © Tony Leukering

On range, these are laingi, and both photos were taken in summer on the same date, so the bird(s) are worn. Although these wrens are still "brown," it is apparent that this race is more colorful and contrasty than either of the Great Basin races. Pyle (1997) describes "cinnamon rump" and "brightish pale cinnamon flanks" for this race, and those characters are still somewhat evident, even in these summer photos. I also see darker and more contrasty crown on these birds.

both photo (left) 21 June 2010 Minot, north-central North Dakota © Brian L. Sullivan

The Eastern Group has six subspecies:

• iliacus from e Saskatchewan and central Manitoba south to the Midwest, taking in the easternmost portions of the Dakotas and Nebraska, and east to Michigan and e Ohio; winters to the Gulf Coast of se U.S. This subspecies apparently intergrades with "western" Marsh Wrens in a broad swathe in the central prairies (detailed on the previous page).
• dissaeptus of the Northeast, from Ontario and c Ohio east to Maine and Massachusetts; winters to the Gulf Coast of se U.S.
• palustris is the nominate race, mostly resident in coastal New York, New Jersey and east-central Virginia.
• waynei is resident from coastal se Virginia through coastal North Carolina.
• griseus is resident from coastal South Carolina to east-central Florida, and
• marianae is resident of the Gulf Coast from east Texas to west Florida.

These subspecies are described in Pyle (1997) and Kroodsma & Verner (1997). This internet project is summarized by a California observer, primarily for use by western birders, and I have neither the resources (i.e., a good set of photos of all races) nor the expertise to discuss regional variation in the Eastern populations.

However, for comparison with western populations, the northeastern race is discussed below.

On range, these are dissaeptus, and both photos were taken in summer on the same date, so the bird(s) are worn. Although these wrens are still "brown," it is apparent that this race is more colorful and contrasty than either of the Great Basin races. Pyle (1997) describes "cinnamon rump" and "brightish pale cinnamon flanks" for this race, and those characters are still somewhat evident even in these summer photos. I also see darker and more contrasty crowns on these birds.

photo (far left) 11 July 12 Great Meadows NWR, MA © Ryan Schain

photo (near left) 29 May 2011 Great Meadows NWR, MA © Ryan Schain