the spelling of the dell's name tends to vary depending on the source. the official oregon state park site spells it with the apostrophe, however the gnis entry omits the apostrophe. oregon geographic names appears to make a distinction between the name of the geographic feature and the name of the state park (now a state natural area), referring to both shepperds dell and shepperd's dell state park. omitting the apostrophe when referring to the dell itself is consistent with the policies of the united states board on geographic names, which strongly discourages the use of possessive apostrophes in geographic names.