Paula,
Please do not apologize. As a friend of mine says, "Birds have wings." The statement, "...Ruby-throated nest 'in Pennsylvania' and could not be in Colorado at this time of year." is painting with a VERY broad brush. Yellow Grosbeaks should be in Mexico. The Golden-crowned Warbler found several years back, "should be in Mexico." Crissal Thrashers and Cactus Wrens should be south of Colorado. Magnificent Frigate birds should be along the southern coasts. The point is, we have found that birds can show up almost anywhere. Summer is a time that birds wander. These "wanderers" could have been lost and off course during spring migration and are now roaming around looking for the proper habitat and/or a mate. This is one way species expand ranges. These "wanderers" could also be post-breeding dispersal birds. Birds that bred earlier this year and are now wandering around (with nothing to do)? Many young birds also disperse once on their own.
I'm not sure if you had a Ruby-throated Hummingbird or not, but maybe! The best we can do when we find what we think is something odd, is document, document, document.
Joey Kellner
Littleton, Colorado