out of jurisdiction ?

live in and was arrested in minnesota,was a couple miles out of city limits, driving toward city, was stopped by city police who said he was called by motorist on cell phone. police came up from behind me. police gave field test (heel to toe) i did not do well,police gave red, yellow, green breath test, turned red right away. city police called county deputy who drove my car to city impound, then city police, county guy & myself drove back to county guys squad car, was taken to county seat (12 miles away) by city police, as the original city destination has very limited police station, (very small town).
was given my option of breath test or blood test took blood option.after blood test i was given ride home by original city police, my wife signed release form, was given no copies of any paperwork or pending charges. is this standard and is it legal for city police to sit outside of city limits waiting for potential dwi drivers.