Unfortunately this specimen has no collection data. It is sorted with a number of apoid wasps from California, so I'm presuming that this is also from CA.
Keyed tentatively to Bembix gillaspyi using Bohart & Menke and Bohart & Horning. Unfortunately the palps are not exposed and the specimen is too old to manipulate safely. Qualitatively, it looks more like Bembix to me than the bembicines with 6-4 palp formula. The development of the ocelli is also a bit tough (tried to get a photo, but I realize the quality is poor).
Presuming that this is Bembix, it keys nicely to B. gillaspyi and matches all visible characters in the description, except I don't see a dorsomedial labral swelling. Probasitarsus has six strong rake setae and one weak seta.
If anyone can suggest further characters that don't involve mouthpart dissection, I can more easily look these up than get better photos.