These are all the places I have been able to find that are called CORWIN.

If you know of any others or have any information to add on any of these listed, please contact me.
 

ALASKA:
-CORWIN Creek Waterway, North Slope county, Alaska
-CORWIN Rock Island, Aleutian Islands, Alaska

CALIFORNIA:
-CORWIN Denney Research Center Building, Los Angeles county, CA

COLORADO:
-CORWIN Junior High School School, Pueblo county, CO

ILLINOIS:
-CORWIN Branch Waterway, Effingham County, IL
-CORWIN School, Logan county, IL
-CORWIN Residential Area, Henry County, IL

INDIANA:
-CORWIN Residential Area, Tippecanoe county,IN(Variant Names:Columbia)

KANSAS:
-CORWIN Residential Area, Harper county, KS

OHIO:
-Arlington Residential Area, Montgomery county,Ohio (Variant Names: Corwin,South Arlington,Vorhees)
-CORWIN, a post-office of Montgomery county, Ohio.
-CORWIN Residential Area, Warren county, Ohio(Variant Names:Corwin Station,Waynesville Station)A small village of Warren county, Ohio, on the Little Miami railroad, 67 miles S. W.from Columbus.
-Taylorsville Residential Area, Highland county,Ohio(Variant Names: New Corwin)
-NEW CORWIN, a post-office of Highland co., Ohio.
-CORWIN Street School (historical) School, Pickaway county,Ohio
-Hardin Residential Area, Shelby county, Ohio(Variant Names:Corwin Station)
-Tom Corwin Residential Area, Jackson county, Ohio

MICHIGAN:
-CORWIN School, Van Buren county, MI
-CORWIN School Number 3, Ottawa county, MI

MONTANA:
-CORWIN Springs Residential Area, Park county, MT

NEVADA:
-CORWIN Residential Area, Eureka county, NV(approx loc, 35 mi N of Eureka)
-CORWIN Post Office (historical) Building, Eureka county, NV(PO Dec 1878-Oct 1879)

NEW YORK:
-CORWIN Residential Area, Niagara county, NY
-CORWIN Cemetery, Niagara county, NY

N. DAKODA:
-CORWIN Township Local Jurisdiction, Stutsman county, ND

PENNSYLVANIA
-CORWINS Corners Residential Area, McKean county,PA(near Derrick City)

TEXAS:
-CORWIN, near the Colorado River twenty-two miles southeast of Burnet in southeastern Burnet County

VERMONT:
-CORWIN Cemetery, Orange county, VT (near Chelsea)

WISCONSIN:
-CORWIN ridge, Richland county, WI (ridge near Valton)
 
 
 

GPS LOCATIONS

CORWINS Corners PA 415556N 0783453W
CORWIN Cemetery VT 435931N 0722501W
CORWIN ridge WI 433058N 0901652W
 
 

Below is under construction
 
 

CORWIN Creek Waterway, North Slope county, Alaska
COWRIN Rock Island, Aleutian Islands, Alaska

CORWIN Denney Research Center Building, Los Angeles county, CA
 

CORWIN Junior High School School, Pueblo county, CO

CORWIN Branch Waterway, Effingham County, IL
CORWIN School, Logan county, IL
CORWIN Residential Area, Henry County, IL

CORWIN Residential Area, Tippecanoe county, IN (Variant Names: Columbia)

CORWIN Residential Area, Harper county, KS

Arlington Residential Area, Montgomery county, Ohio (Variant Names: Corwin,
South Arlington, Vorhees)
CORWIN, a post-office of Montgomery county, Ohio.
CORWIN Residential Area, Warren county, Ohio (Variant Names: Corwin Station,
Waynesville Station) A small village of Warren county, Ohio, on the Little Miami
railroad, 67 miles S. W. from Columbus.
Taylorsville Residential Area, Highland county, Ohio(Variant Names: New Corwin)
NEW CORWIN, a post-office of Highland co., Ohio.
CORWIN Street School (historical) School, Pickaway county, Ohio
Hardin Residential Area, Shelby county, Ohio (Variant Names:Corwin Station)
Tom Corwin Residential Area, Jackson county, Ohio
 

CORWIN School, Van Buren county, MI
CORWIN School Number 3, Ottawa county, MI

CORWIN Springs Residential Area, Park county, MT

CORWIN Residential Area, Eureka county, NV (approx loc, 35 mi N of Eureka)
CORWIN Post Office (historical) Building, Eureka county, NV (PO Dec 1878-Oct 1879)

CORWIN Residential Area, Niagara county, NY
CORWIN Cemetery, Niagara county, NY

CORWIN Township N. DAKODA
 
 
 
 
 

CORWIN, TEXAS. Corwin, near the Colorado River twenty-two
miles southeast of Burnet in southeastern Burnet County, was settled
in the mid-1850s. A post office was established there in 1870, with
Thomas T. Word as postmaster. It was discontinued in 1882 but
reestablished in 1884. That year Corwin had a district school, a
steam gristmill and cotton gin, three churches, and seventy-five
residents; cotton and wool were the principal shipments from the
area. By 1896, however, the community's population had dropped to
twenty. The post office was discontinued in 1899, and mail for the
community was sent to Double Horn. Area children attended the
Lewis School, which opened in 1888; it operated until 1913, after
which time students attended the school at Spicewood. The
community was not shown on the 1948 county highway map.