a. Cities, rivers, oceans, lakes, mountains, etc.
Chicago
Mississippi River
Atlantic Ocean
Lake Superior
Pike’s Peak
Strawberry Hill.
Note that the generic terms ocean, lake, mountain and the like are capitalized only when they are an actual part of the name itself. We would say “The Atlantic Ocean lies east of the United States,” but we would say “The states which form the North American republic look out on two great oceans, the Atlantic and the Pacific.”
The following tables are taken from A Manual for Writers by John Matthews Manley and John Arthur Powell (University of Chicago Press, Chicago).
Subject to the rule just stated, they will be found very useful.
Capitalize, in singular form only, when immediately following the name
Archipelago
Borough
Branch (stream)
Butte
Canyon
County
Crater
Creek
Delta
Forest
Fork
Gap
Glacier
Gulch
Harbor
Head
Hollow
Mesa
Narrows
Ocean
Parish (La.)
Park
Plateau
Range
Reservation
Ridge
River
Run
Capitalize in singular or plural form when immediately following the name
Hill
Island
Mountain
Spring
Capitalize, in singular form, either before or after the name; and in plural form before the name