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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 ridelogs 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 riders are riding a trail in its intended direction.
  • > 96%
  • > 90%
  • > 80%
  • > 70%
  • > 50%
  • < 50%
  • bi-directional trail
  • no data
Trail Last Ridden
Trailforks scans ridelogs 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 ridelogs 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 rides = more kinetic energy = warmer colors.
  • most popular
  • popular
  • less popular
  • not popular
ATV/ORV/OHV Filter
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Radar Time
x Activity Recordings
Trailforks users anonymized public ridelogs from the past 6 months.
  • mountain biking recent
  • mountain biking (>6 month)
  • hiking (1 year)
  • moto (1 year)
Activity Recordings
Trailforks users anonymized public skilogs from the past 12 months.
  • Downhill Ski
  • Backcountry Ski
  • Nordic Ski
  • Snowmobile
Winter Trails
Warning A routing network for winter maps does not exist. Selecting trails using the winter trails layer has been disabled.
x 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 riders jump on trails. Zoom in to see individual jumps, click circles to view jump details.
Trails Deemphasized
Trails are shown in grey.
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      No description for Big Rock / Lucas Valley has been added yet! Login or register to submit one.
      Activities Click to view
      Region Details
      • 11
      • 8
      • 9
      • 4

      Region Status
      Caution as of 10 hours
      Local Trail Association

      Stats

      Avg Trail Rating
      Trails (view details)
      41
      Trails Mountain Bike
      32
      Trails Horse
      17
      Trails Hike
      40
      Trails Trail Running
      40
      Total Distance
      46 miles
      Total Descent
      19,783 ft
      Total Vertical
      1,791 ft
      Highest Trailhead
      1,870 ft
      Reports
      234
      Photos
      148
      Ridden Counter
      4,428

      Photos of Big Rock / Lucas Valley Mountain Bike

      trail: 680
      36 |
      Apr 11, 2023 @ 8:37pm
      Apr 11, 2023
      trail: 680
      19 |
      Apr 11, 2023 @ 8:37pm
      Apr 11, 2023
      18 |
      Apr 11, 2023 @ 7:10pm
      Apr 11, 2023
      trail: 680
      15 |
      Apr 11, 2023 @ 7:09pm
      Apr 11, 2023
      trail: 680
      25 |
      Apr 11, 2023 @ 7:09pm
      Apr 11, 2023
      trail: 680
      22 |
      Apr 11, 2023 @ 7:08pm
      Apr 11, 2023
      trail: 680
      19 |
      Apr 11, 2023 @ 7:08pm
      Apr 11, 2023
      trail: 680
      9 |
      Apr 11, 2023 @ 7:08pm
      Apr 11, 2023

      Videos of Big Rock / Lucas Valley Mountain Bike

      Big Rock
      0:09 | 222 | Sep 27, 2017
      BRAKE FADE!!!!!!!!!!!!
      trail: Rotor Burn
      2:17 | 133 | Jul 14, 2016
      Halloween shenanigans
      trail: Halloween
      2:53 | 393 | Nov 1, 2014
      680 to Solstice
      trail: 680
      8:41 | 812 | Jan 21, 2013
      Big Rock Trail / Marin County Flow &...
      7:15 | 214 | Feb 8, 2022 , Lucas Valley - Marinwood
      Rehab Solo Ride to Recovery
      trail: Halloween
      2:04 | 673 | Nov 23, 2009
      Halloween Shuttle Ride
      trail: Halloween
      2:10 | 455 | Nov 1, 2009
      Luiz Fire Road dirt/gravel road trail located...
      8:42 | 166 | Aug 27, 2021 , Lucas Valley - Marinwood

      Recent Trail Reports

      Activity Feed

      usernameactiontypetitledate
      kyvanleeaddreportactivity #51095978 and 2 more
      Apr 12, 2024 @ 5:35pm
      10 hours
      mikeKDukU4wishlistregionactivity #50863023
      Apr 6, 2024 @ 12:40pm
      Apr 6, 2024
      lendersonvotetrailactivity #50411101 and 1 more
      Mar 24, 2024 @ 1:19pm
      Mar 24, 2024
      lendersoncommenttrailactivity #50411082 and 1 more
      Mar 24, 2024 @ 1:18pm
      Mar 24, 2024
      awaiteaddreportactivity #50195276
      Mar 19, 2024 @ 11:18am
      Mar 19, 2024

      Recent Comments

      usernametypetitlecommentdate
      lendersontrailQueenstone TrailReally not that fun. Slightly better than...
      Mar 24, 2024 @ 1:57pm
      Mar 24, 2024
      lendersontrailRotor BurnNot worth the climb. This is not a trail, just...
      Mar 24, 2024 @ 1:18pm
      Mar 24, 2024
      KetwonbettrailButterfield Fire RoadVery steep fire road that can be used to climb...
      Jan 20, 2024 @ 9:22pm
      Jan 20, 2024
      KetwonbettrailGoat TrailFun bike-legal trail. Can have sketchy...
      Jan 20, 2024 @ 9:12pm
      Jan 20, 2024
      Cport7trailBurnt Ridge Fire RoadAn easement would be wonderful. Open the...
      Nov 11, 2023 @ 9:00pm
      Nov 11, 2023

      Local Badges


      Activity Type Stats

      activitytypetrailsdistancedescentdescent distancetotal verticalratingglobal rankstate rankphotosreportsroutesridelogs
      Mountain Bike3241 miles15,627 ft26 miles1,759 ft
      #4,705#2,1191482328,732
      Horse178 miles2,503 ft5 miles827 ft
      311
      Hike4045 miles18,625 ft29 miles1,791 ft
      #3,850#1,950234363
      Trail Running4045 miles18,625 ft29 miles1,791 ft
      #3,869#1,956234224
      • By brenthillier NSMBA TRAILFORKS & contributors
      • Admins: A4B, A4B, MCBC
      • #3979 - 10,446 views

      Downloading of trail gps tracks in kml & gpx formats is enabled for Big Rock / Lucas Valley.
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