Keystone Ancient Forest Hiking in Fall: What to Know

A friend drove out to Keystone Ancient Forest on a Monday afternoon last spring, pulled up to a locked gate, and turned around without ever seeing a tree. That story gets repeated all over Sand Springs, usually as a complaint about a park that only opens four days a week. But the schedule at Keystone Ancient Forest was never really about keeping people out. It was built around a handful of specific commitments the city made when it created the preserve, and every one of those commitments happens to line up in the hiker's favor once the calendar turns to fall.

That is the part most people miss. The rules that feel like restrictions in July become instructions in October and November. Here is why, trail by trail.

The Hours Are a Staffing Decision, Not a Mood

Keystone Ancient Forest is open Thursday from 7 a.m. to 2 p.m., then Friday through Sunday from 7 a.m. to 6 p.m. That six-hour gap on Thursdays throws people off every week, and it is easy to read the whole schedule as arbitrary. It is not. The 1,360-acre preserve sits west of Sand Springs on land the city bought with $1.4 million in federal transportation funds between 2001 and 2002, under a conservation easement it later signed over to The Nature Conservancy in 2015. That arrangement means the forest is managed as protected old growth rather than as a standard city park, staffed in part by Parks Department employees and volunteer trail guides who greet hikers at the visitor center and walk them through what to expect. The gate schedule, including the shorter Thursday window, follows from that same conservation-first approach rather than an effort to cap how many people can get in.

Fall is the one season where that four-day-a-week window stops mattering as much. Cooler afternoons mean a two-hour window on Thursday can cover a full loop that would have been miserable at 2 p.m. in August, and the extended Friday-through-Sunday hours give a full weekend to work with before the days get noticeably shorter heading into November.

Every Trail Runs Through the Same Corridor

The preserve has more than 12 miles of marked trail, but the layout is not a web of options branching off the parking lot. It is one spine with everything else hanging off it. The Fire Road Trail runs 0.8 miles from the trailhead with a gradual uphill climb, and it is the only way to reach the Less Traveled Trail, the Savanna Trail, or the Falls Trail. Want to see the Falls Trail's waterfalls? You walk the Fire Road first. Want the newer Savanna Trail? Same corridor. The trail system looks like this from the visitor center:

• Childers Trail — 0.6 miles, paved and ADA accessible, named for the Sam Childers family, who donated the land it crosses
• Fire Road Trail — 0.8 miles, the connector every other trail depends on, with a gentler route to the Washington Irving overlook than the switchbacks on the Frank Trail
• Falls Trail — a 3.5-mile difficult loop opened in 2021, with two intermittent waterfalls and roughly 500 feet of elevation gain
• Savanna Trail — a short loop unveiled in 2025 around a 10-acre pollinator savanna

That single-corridor design is a direct result of how the land was assembled and protected. It was never built for volume. It was built to concentrate foot traffic on one route so the rest of the old growth stays undisturbed, which is also why off-trail hiking is not permitted anywhere in the preserve.

The Falls Only Run When Fall Delivers Rain

The Falls Trail is the payoff for that walk up the Fire Road, but it comes with a catch nobody mentions until they have already made the drive. Both waterfalls on the trail are intermittent. They are not fed by a year-round spring. They run when recent rain has fed the creek drainages, and they are typically at their best one to two days after a rain event, then they thin out again as the ground dries.

This is where fall stops being a scheduling inconvenience and becomes the actual reason to go. Spring and fall are already the two seasons locals point to for the most comfortable hiking temperatures here, and fall rain is common enough in this part of Oklahoma that timing a visit two mornings after a storm is a realistic plan rather than a guess. Summer hikers on the Falls Trail are often working around heat advisories that can shorten hours or close exposed sections entirely. Fall hikers get the temperature and the water at the same time, if they pay attention to the forecast instead of just the calendar.

The Newest Trail Was Funded, Not Just Planned

The Savanna Trail did not exist a few years ago. It grew out of a butterfly savanna the Parks Department started building after Webco Industries, the Sand Springs manufacturer, donated $10,000 in seed money to kick off the project. Dana Weber, Webco's CEO, described the pairing of an industrial company funding a pollinator habitat in blunt terms at the time.

"It all fits together. It's like a huge ecosystem."

The 10-acre savanna now sits at the point where three trails converge, seeded with native wildflowers meant to support monarch migration, and the short loop trail built around it opened in 2025.

The accessibility side of the preserve has its own donor story. In 2022, a $25,000 gift from Phillips 66 paid for two Trackchairs, motorized all-terrain wheelchairs with tank tread instead of wheels, which let hikers with mobility limitations reach sections of the Childers, Frank, Savanna, and Fire Road trails that standard wheelchairs cannot handle. The Falls Trail, Wilson Trail, and Less Traveled Trail remain out of reach for the chairs because of narrow, primitive terrain, but that still opens most of the preserve's core routes to visitors who would otherwise be limited to the short paved loop.

The Dog Days That Actually Land on a Free Weekend This Fall

Leashed dogs are only allowed inside the forest on the first Saturday and the third Sunday of each month, a rule that trips up almost every first-time visitor who assumes a public nature preserve means bring-your-dog-anytime. For anyone planning around this fall, the actual dates line up as September 20, October 3, October 18, November 7, and November 15.

That two-day-a-month window exists for the same reason the overall hours are limited: this is a preserve managing foot traffic through 300-year-old post oaks and 500-year-old cedars, not a dog park with trees in it. Missing the window by a day means turning around, so the calendar matters more here than at almost any other trail system in the Tulsa area.

Why the Fine Print Is the Point

Keystone Ancient Forest became the first property in Oklahoma inducted into the Old-Growth Forest Network, a distinction tied directly to the same conservation choices that produce the limited hours, the single-corridor trail layout, and the twice-monthly dog schedule. None of those rules are there to make a visit harder. They are the terms that kept this specific stretch of cross timbers forest intact long enough to still have 500-year-old cedars standing in it.

The preserve also hosts the Ancient Trail Trek each February, a 5K, 10K, and 15K trail race that draws runners through the same corridor system described above, proceeds going back into park maintenance. It is worth knowing about even in September, because it is a preview of how the trail network handles a crowd, and it tends to answer any lingering questions about which sections are runnable and which stay technical no matter the season.

Fall does not change any of the rules at Keystone Ancient Forest. It just happens to be the six-to-eight-week stretch each year when the rain, the temperature, and the calendar line up with the schedule instead of against it. Anyone who has lived in Sand Springs for a while probably already knows the gate locks on Mondays. Fewer know that the whole system was built this way on purpose, or that this is the season it finally works the way it was designed to.

If you are weighing a move to Sand Springs, or already live here and are curious what else has changed in the neighborhoods around Tulsa, Jill Falkenberry has spent nearly three decades getting to know this part of Green Country up close. Take a look at the Sand Springs neighborhood guide for more on what makes this community worth exploring, and reach out any time. Let's Connect.