Open in App
Get this trail on your phone instantly.
more stats
1.8 miles
Distance
683 ft
Climb
-213 ft
Descent
00:43:46
Avg time
469 ft
Altitude change
8,744 ft
Altitude min
9,315 ft
Altitude max
8,744 ft
Altitude start
9,213 ft
Altitude end
5%
Grade
-34.7%
Grade max
65.1%
Grade min
1 mile
Distance climb
3,025 ft
Distance down
220 ft
Distance flat
00:43:46
Avg time
Trail Details
-
Activities
- Mountain Bike
- Horse
- Hike
- Trail Running
-
Riding AreaKirkwood Mountain Resort
Kirkwood, California -
Ref Number#17E22
-
Difficulty Rating
-
Local Popularity85 in Mountain Biking [+]
- 100 in Trail Running
- 95 in Hiking
- 5 in Horseback
-
Global Ranking
-
Hiking SAC ScaleT2 Mountain Hiking
-
Trail TypeSingletrack
-
Bike TypeAM, XC
-
DirectionUphill PrimaryPopular Direction Shown
-
Climb DifficultyBlack Diamond
-
Physical RatingModerate
-
Trail VisibilityAlways easy to follow
-
Alpine TrailYes
-
Dogs AllowedYes
-
eBike Allowed
No community description for Thunder Mountain Loop (Sentinels) trail has been added yet!
AI Generated Description
Thunder Mountain Loop (Sentinels) is a 2 mile popular blue difficulty alpine singletrack trail located near Kirkwood California. This multi-use trail can be used uphill primary and has a moderate overall physical rating with a 683 ft black diamond climb. Trail visibility is always easy to follow. On average it takes 43 minutes to complete this trail.
Bike Park
Traditionally Indigenous Territory
Recent Activity on Trail
Past Week
- 1 rides
- 25 miles average
6 Months
- 25 rides
- 13 miles avg distance
All
- 82 rides
- Last: Sep 15, 2026
| c1 | c2 | c3 | c4 |
|---|---|---|---|
January | February | March | April |
May | June | July | August |
September | October | November | December |
Thunder Mountain... Trail Reports
more »
close
-
Layers w
- Weather Layers
- Pro
- Pro
- Pro
- Pro
- Pro
- Pro
- More Layers
- Pro
- Pro
- Pro
- Pro
-
Upgrade to
3D
Trail Conditions
- Unknown
- Snow Groomed
- Snow Packed
- Snow Covered
- Snow Cover Partial
- Freeze/thaw Cycle
- Icy
- Prevalent Mud
- Wet
- Variable
- Ideal
- Dry
- Very Dry
Trail Flow (Ridden Direction)
Trailforks scans users activity logs to determine the most popular direction each trail is ridden. A good flowing trail network will have most trails flowing in a single direction according to their intension.
The colour categories are based on what percentage of users are riding a trail in its intended direction.
The colour categories are based on what percentage of users are riding a trail in its intended direction.
- > 96%
- > 90%
- > 80%
- > 70%
- > 50%
- < 50%
- bi-directional trail
- no data
Trail Last Used
Trailforks scans activity logs to determine the last time a trail was ridden.
- < 2 days
- < 1 week
- < 2 weeks
- < 1 month
- < 6 months
- > 6 months
Trail Ridden Direction
The intended direction a trail should be ridden.
- Downhill Only
- Downhill Primary
- Both Directions
- Uphill Primary
- Uphill Only
- One Direction
Contribute Details
Colors indicate trail is missing specified detail.
- Description
- Photos
- Description & Photos
- Videos
Trail Popularity ?
Trailforks scans activity logs to determine which trails are ridden the most in the last 9 months.
Trails are compared with nearby trails in the same city region with a possible 25 colour shades.
Think of this as a heatmap, more activities = more kinetic energy = warmer colors.
- most popular
- popular
- less popular
- not popular
ATV/ORV/OHV Filter
Max Vehicle Width
inches
US Cell Coverage
Legend
Radar Time
Activity Recordings
Trailforks uses anonymized public activity data.
?
Activity Recordings
Trailforks uses anonymized public activity data.
?
Winter Trails
Warning
A routing network for winter maps does not exist. Selecting trails using the winter trails layer has been disabled.
Missing Trails
Most Popular
Least Popular
Trails are colored based on popularity. The more popular a trail is, the more red. Less popular trails trend towards green.
Jump Magnitude Heatmap
Heatmap of where users jump on trails. Zoom in to see individual jumps, click circles to view jump details.
BC Backroad Status
![map legend]()
Service Road Atlas is a free to use, community-driven service for viewing and creating reports on the numerous back-country service roads around B.C. and Alberta.
Slope Aspect
Direction the slope faces
Trails Deemphasized
Trails are shown in grey.
Only show trails with no bike usage.
Suggested Layers
Based on selected activity type
Save the current map location and zoom level as your default home location whenever this page is loaded.
Save
Directions to thunder-mountain-loop-sentinels trailhead
(38.696280, -120.088260)
Photos
3 more »
Routes with this trail
25 miles • 4,802 ft • 16 •
VIRTUAL Kirkwood Kruise MEGA RIDE!! Our second Virtual Route of the summer goes live September 1st through...
16 miles • 3,496 ft • 11 •
This is the Advanced Route for the Peak Pursuits women's mountain bike event, September 19-21, 2025.
12 miles • 2,623 ft • 7 • Loop •
scxsKqV0
The last section to the summit is undoubtedly double black diamond.
PeterNFi1uy
Yeah this ain’t a blue. There is basically mandatory hike a bike near the summit.
We hope you've been enjoying Trailforks!
Create a FREE account to view all trail reviews and much more.
Nearby Trails
- Sentinel Trail 33 ft
- Kirkwood Lake Spur 3,786 ft
- Meadow Trail 4,495 ft
- Meadow Trail Access 5,135 ft
- Jobe's Jaunt 5,223 ft
Kirkwood Mountain Resort
- By TheAngryTomato TRAILFORKS & contributors
- #316509 - 1,946 views
- Follow/Subscribe
- login to download gpx or kml files.
Hit the Trail
Download Trail
Save to wishlist, Garmin & download.
Find Related Routes
Find routes and users activities that include this trail.
You must enter a description before submitting.