Running stores as sponsors
People who participate in running events are runners. They all buy running shoes. A large number of them buy shoes - and, often, other gear - at running specialty stores. Those stores can be very valuable sponsors for your event.
Running stores cater to the same markets as your event. You need each other's customers. And stores often possess multiple resources that can meet the needs of your event.
They have supplier relationships that can help connect you with potential sponsors that you can't reach. They may own tents, generators, or other equipment you can use for your race. They sometimes have cadres of volunteers who can staff your event.
The stores are convenient locations for packet pickup. They'll benefit from being promoted in all of your registration materials and will relish the prospect of all of your runners coming into their stores (you are bringing them business).
Store owners are usually astute marketers and may be able to create promotional opportunities that will benefit both the store and your event.
Competitor Magazine will release, next month, the winners of the "50 Best Running Stores in America" awards. If one of those stores is in your community, it may be a good idea to approach it with a sponsorship proposal.
The #1 ranked store in the competition was Naperville Running Company, in Naperville IL (a Chicago suburb). Others in the top four were, Fleet Feet Sports - Chicago (Chicago IL), Swag's Shoes (Louisville KY), and Run On! (Dallas TX).