triangular with lights.....seen by town sheriff also upon arrival at cousins farm in johnstown colorado

this is second hand...but in the mid seventies.....my cousins witnessed a triangular ufo...just south of the town of johnstown co...on their farm...near the town power plant.  They called the sheriff...whom also witnessed the craft stil there when he arrived....after some time...the craft slowly moved parallel to the ground..away...and the police chased it as best they could...and it dissappeared over the ridge.   I believe that the airforce or military department, instructed my cousins to hush up about the event...as they were very reluctant to ever speak of it again.....My cousins last name was DAY....one name was FRANK...the father of my first cousins....He was my mothers age.....at this time i would have been 13 or 14 years old. and Frank Day...now deceased was about 37 or 38.  can you please investigate this...as it must have been a very serious event...covered up...thank you ((name and personal data deleted))…