Legal Question in Intellectual Property in California

Re: trademark infringment

It depends on several factors, including whether or not you are in the same line of business as the registrant (and whether a consumer could believe that the registrant would expand into your line of business).

It also depends on whether the "Tulip Hill" region is known for putting on your type of event.

You should consult an intellectual property attorney for advice.

Re: trademark infringment

It would depend on what category the names are registered under. Trademark protection extends to the scope that the Trademark owner defines in its application. It would just take some research.

Re: trademark infringment

As the preceding two answers have pointed out, whether infringement exists is a question of fact that depends upon the product or service category or categories covered by the trademark, the category of the alleged infringer, the likelihood of marketplace confusion, and related factors. For example, there is a Tulip Hill Winery in Lake County, and its brand is distributed statewide, so naming a wine festival "Tulip Hill" in El Dorado County would be unwise.

On the other hand, trademarking the combination of two fairly common English words does not give the trademark holder a monopoly on the use of the words or the combination. Tulip Hill Winery (for example only, I have no idea whose trademark rights concern you) could not reasonably object to your use of the phrase to describe a florists' convention or for a rock concert.