Drive up 59th Avenue toward Thunderbird Conservation Park on a Saturday morning and you'll find orange fencing where the parking lot used to be. Keep going to 55th Avenue and you'll find the same thing. For anyone who has spent the last few years pulling into either lot before a sunrise loop around Arrowhead Point, this is the first fall in recent memory when both of those entrances are shut down at once.
That overlap is the part nobody spells out clearly. Glendale published each trailhead's closure window separately, in press releases and local news stories that came out months apart, and read in isolation they sound like a rotation: one lot closes, the other two stay open, everybody adjusts. Stack the three schedules next to each other and a different picture shows up. The 59th Avenue trailhead, the busiest entry point into the park, closed on April 6, 2026 and stays closed through December. The 55th Avenue trailhead closed in August and won't reopen until February 2027. Those two windows overlap for five months, from August through December of this year, which means right now the only functioning trailhead at Thunderbird Conservation Park is the one off 67th Avenue.
Why the schedule looks staggered but isn't, quite
Glendale's parks department has been clear that the goal is to keep at least one entrance open throughout the roughly 16 to 18 month project. That's technically true for the whole timeline, but it undersells how narrow the access gets at two separate points. Right now, through the end of December, 67th Avenue is doing the work of all three lots. Then there's a short window where 59th Avenue reopens while 55th Avenue is still closed, followed by a second single-entrance stretch in January and February 2027, when 67th Avenue closes for its own turn and 59th Avenue becomes the only way in while 55th Avenue is still finishing up. The park doesn't return to three open trailheads until around August 2027, which is also when the city expects the entire project to wrap.
Glendale Parks and Recreation Director John Kennedy has been straightforward about what's actually affected. "These are just affecting the trailheads," he told local reporters when the first closure began in April. "The trails will remain open throughout the project." That distinction matters more than it sounds like it should. The roughly 15 miles of multi-use trail that wind through the park's 1,185 acres in the Hedgpeth Hills aren't going anywhere. What's closed is where you park your car.
What's actually getting built
The construction isn't cosmetic. Each trailhead is getting repaved parking, new restrooms, shade structures, and updated signage, along with native plant landscaping around the lots. The city has framed it as an overdue upgrade for a park that has served the area for roughly 70 years, and the stated aim is safer traffic flow in and out of the lots along with a better first impression at the entrances. None of that touches the trail surface itself. The saguaro, cholla, and palo verde that line the Coach Whip and Cholla Loop trails are staying exactly where they are.
Getting to the trail you actually want
With 59th Avenue and 55th Avenue both out of commission, the 67th Avenue lot, sometimes still labeled on older park maps as the Thunderbird Park Trailhead near Patrick Lane, is carrying the bulk of foot traffic. That's a fine starting point if your plan is the Cholla Loop, which runs about 3 miles, or a stretch of Coach Whip, the park's longest route at 9.6 miles out and back with just over 1,000 feet of elevation gain.
It's a longer walk if your usual route is one of the summit loops. The 59th Avenue lot has historically served as the primary access point for Arrowhead Point, North Thunderbird Peak, and the Hedgpeth Hills Highpoint, the three-peaks stretch that draws hikers up onto the ridgeline for the wide views back toward Phoenix. With that lot closed, reaching those summits from 67th Avenue means picking up Coach Whip first, following it toward the pedestrian bridge that crosses 59th Avenue, and connecting into the Arrowhead Point loop from there, adding real mileage to what used to be a shorter out-and-back from the south side. The Three Peaks Loop itself covers 7.3 miles with about 1,400 feet of elevation gain when you start from its usual access point, so the detour is worth planning for rather than discovering halfway through a hike in September heat.
What this means for the next few months
If Thunderbird Conservation Park is part of your regular rotation, whether that's an early lap before work or a Saturday morning with the dog, the practical move for the rest of this year is to default to 67th Avenue and expect a longer approach to anything on the park's northern half. That holds through December. Once 59th Avenue reopens, the equation flips for a few weeks, and then flips again in January when 67th Avenue takes its turn under construction while 55th Avenue is still finishing up. The two single-entrance windows, this fall and again in January and February, are the stretches worth marking on a calendar if precise trailhead access matters to your routine.
The city has said it expects the full project done by late summer 2027, at which point all three trailheads reopen with new restrooms, shade, and paved lots in place. Until then, Glendale's parks department has been posting current trailhead status on its website, and that's the most reliable place to confirm access before heading out, since the schedule has shifted slightly in different reports over the past several months.
If you're spending time in the neighborhoods around the Sonoran foothills and want a read on how something like this actually plays out day to day, not just what the press release says, that's the kind of local detail The Nelson Group SW - Jennifer tracks and is happy to talk through.
