Directions to Boulder Reservoir, which has access from 3 locations, are provided in the county birding guide:
According to the website (
https://bouldercolorado.gov/parks-rec/reservoir-hours-and-fees), the gates to the main entrance on 51st Street open at 7:00 AM and close at 6:00 PM. Any cars inside must be out by 7:00 PM. Hours change on October 1. There is no admission fee this time of year, and the staff at the entrance gate is friendly to birders. The main entrance provides access to the marina, boat ramp, and dam on the south side of the lake, and also offers views into Sixmile Reservoir, which is private, just south of Boulder Reservoir.
Otherwise, access to Boulder Reservoir is from the trailheads on the northwest and northeast sides.
David Dowell
Longmont, CO