Thanks for the vote of confidence and yes, we did allude to the limits of the Strip in the April 1 QoD regarding the new marijuana dispensary that's claiming to the the first and only such facility "on the Strip." Our answer was not an April Fool's joke, however and Sahara Avenue does indeed designate the northernmost limit of that section of Las Vegas Boulevard known as "the Strip."
Here's that clarification you requested: Though commonly considered to be the "heart" of Las Vegas by the outside world for the past several decades, that approximate 4.2-mile stretch of Las Vegas Boulevard known as the Strip is not located in Las Vegas at all, but is actually in the unincorporated towns of Paradise and Winchester, although you're not mistaken in observing that many travel guides choose to push the limit another 0.4 miles further north and include the Stratosphere Tower (it's an error of which Bob Stupak would certainly approve, even if bureaucrats and purists do not). Officially, however, today it's SLS Las Vegas that's the Strip's most northerly casino; originally, it was the El Rancho Vegas, located across the street at 2500 Las Vegas Boulevard and which, when it opened in 1941, signaled the birth of a new resort-casino axis, entirely distinct from Downtown.
By the same token, the southern limit of the Strip has also proven to be somewhat fluid: Originally, Tropicana Avenue was said to mark the boundary, but as the construction of additional megaresorts continued seamlessly to the south, the goal posts were moved to reflect that. Before it was imploded in 2006, the Hacienda was considered to mark the conclusion of the Strip at its southernmost point, although some maps and travel guides omitted it; today, Mandalay Bay at Russell Road marks the spot, while the famous "Welcome" sign is about 0.3 miles to the south. (Note that on New Year's Eve, when "the Strip" traditionally is closed to vehicular traffic, it's that same stretch of the boulevard, between Russell and Sahara, to which the pedestrian-only policy applies.)
As to where the name came from, credit is given to a cop named Guy McAfee who began his career as a firefighter in California before moving on to become head of the vice squad of the Los Angeles Police Department, where he became known as the "Al Capone of L.A." thanks to his outside business interests, which extended to the saloon, casino, and brothel business, including an establishment named the Clover Club on Sunset Strip. When the new mayor of the city implemented a crackdown on organized crime in the late '30s, McAfee upped and relocated to Las Vegas, where he rapidly gained interests in a number of casino properties on Las Vegas Boulevard, which he dubbed "the Strip" as in, the "Sunset Strip of Las Vegas."
