| 1/1/1876 by CGS (MONUMENTED) |
|
| 1/1/1852 by CGS (GOOD) |
| DESCRIBED BY COAST AND GEODETIC SURVEY 1852 (RDC)
THE STATION WAS NOT OCCUPIED. OBSERVATIONS WERE MADE TO THE FLASHING RED BEACON LIGHT ABOUT 40 FEET ABOVE THE STATION MARK. |
| 1/1/1935 by CGS (GOOD) |
| RECOVERY NOTE BY COAST AND GEODETIC SURVEY 1935
ABOUT 30 MILES EAST OF BERKELEY AND OAKLAND, ABOUT 15 MILES BY ROAD EAST OF WALNUT CREEK, AND ABOUT 15 MILES BY ROAD NORTHEAST OF DANVILLE, ON SUMMIT OF MOUNT DIABLO, MOST PROMINENT LANDMARK IN VICINITY AND A STATE PARK. AT WEST END OF PARKING SPACE ON SUMMIT IS MOUNT DIABLO, AIRWAY LANDMARK BEACON (SEE BELOW). AT EAST END OF SUMMIT IS SMALL WOODEN OBSERVATION TOWER BUILT OVER ROCK OUTCROP WHICH FORMS HIGHEST PART OF SUMMIT. FROM THIS POINT SUMMIT BREAKS OFF STEEPLY IN ALL DIRECTIONS EXCEPT WEST. STATION IS UNDER NORTHWEST PART OF THIS PLATFORM, 3 FEET NORTHWEST OF CONCRETE PIER WHICH IS AT CENTER OF PLATFORM AND AROUND WHICH RANGE FINDERS ARE CENTERED. IN 1852 STATION WAS MARKED BY HOLE ABOUT 2 INCHES IN DIAMETER AND 1-1/2 INCHES DEEP IN CENTER OF BOTTOM OF ANOTHER HOLE 8 INCHES IN DIAMETER AND 6 INCHES DEEP. IN 1858 A 1/2-INCH HOLE WAS DRILLED IN ROCK. IN 1876 COPPER BOLT WITH CROSSLINES ON TOP WAS SET IN SOLID ROCK. OVER THIS WAS PLACED PIER WITH 3/4-INCH COPPER BOLT MARKED WITH CROSSLINES CEMENTED FLUSH IN TOP. IN 1892 HOLE AT INTERSECTION OF CROSSLINES IN UPPER BOLT WAS FOUND ECCENTRIC TO TRUE STATION, AND CENTER WAS RE-MARKED WITH NEW CROSSLINES 3/16 INCH SOUTHEAST OF HOLE. IN 1922 TOP OF PIER FOUND IN RUINS AND MARK RECOVERED DESCRIBED AS 1/2-INCH COPPER BOLT WITH CROSSLINES IN TOP SET FIRMLY IN, AND PROJECTING 1/8 INCH ABOVE BEDROCK. OLD PIER HAD THREE OPENINGS AT BASE TO PERMIT ACCESS TO MARK. PIER WAS REPAIRED, AND ON IT WAS PLACED CONCRETE CAP 20 INCHES HIGH, MARKING TOTAL HEIGHT OF PIER ABOUT 4 FEET. IN CENTER OF CONCRETE CAP WAS HOLE 6 INCHES SQUARE TO PERMIT ACCESS TO MARK. IN 1935 REPORTED THAT BRICK AND CONCRETE PIER HAD OPENING ON NORTH SIDE TO PERMIT ACCESS TO MARK AT GROUND LINE. PIER WAS REPORTED TO EXTEND 3 FEET ABOVE OBSERVATION PLATFORM. IN 1876 VERTICAL-ANGLE PIER WAS BUILT 144.74 FEET WEST OF STATION. BRICK LATITUDE PIER, 27.7 FEET SOUTHWEST OF VERTICAL-ANGLE PIER AND 167.82 FEET WEST OF STATION. AND TRANSIT-INSTRUMENT PIER, 32.5 FEET SOUTHWEST OF VERTICAL-ANGLE PIER. IN 1922 ONLY BASE OF VERTICAL-ANGLE PIER WAS FOUND. GRADING OF SUMMIT MAY HAVE DESTROYED OTHER OLD AUXILIARY PIERS. IN 1922 REPORTED THAT TWO STANDARD REFERENCE DISKS WERE SET IN SOLID ROCK, BUT DATA FURNISHED FOR THREE REFERENCE MARKS AS FOLLOWS--NO. 1, 2.41 METERS (7.9 FEET) FROM STATION. REFERENCE MARK NO. 2, 3.05 METERS (10.0 FEET) FROM STATION. REFERENCE MARK NO. 3, 17.14 METERS (56.2 FEET) FROM STATION. IN 1935 NO. 1 WAS RECOVERED IN GOOD CONDITION, REPORTED TO BE UNSTAMPED. IN 1931 NO. 2 REPORTED UNDER OBSERVATION PLATFORM. NO. 3 NOT RECOVERED IN 1932. MOUNT DIABLO, FLAGPOLE (SEE DESCRIPTION THEREOF) IS 14.70 METERS (48.2 FEET) FROM STATION. MOUNT DIABLO, AIRWAY LANDMARK BEACON (SEE DESCRIPTION THEREOF) IS 65.51 METERS (214.9 FEET) FROM STATION. |
| 1/1/1938 by CGS (GOOD) |
| RECOVERY NOTE BY COAST AND GEODETIC SURVEY 1938 (LAM)
A COPY OF STANDARD OIL BULLETIN PUBLISHED BY THE STANDARD OIL COMPANY OF CALIFORNIA WAS SENT TO THE U.S.C. AND G.S. WASHINGTON OFFICE BY LEWIS A. MC ARTHUR, PORTLAND, OREGON. THIS BULLETIN CONTAINED A DESCRIPTION OF MOUNT DIABLO AND PHOTOGRAPHS WHICH SHOW THE TRIANGULATION STATIONS THEREON, MOUNT DIABLO, MOUNT DIABLO, FLAGPOLE, AND MOUNT DIABLO, AIRWAY LANDMARK BEACON.
ANOTHER LETTER FROM MR. MC ARTHUR DATED APRIL 20, 1938, IN REGARD TO THE INTERSECTION OF THE MOUNT DIABLO MERIDIAN AND THE MOUNT DIABLO BASE LINE STATES--
CAPTAIN LUKENS SAYS THAT CUTTS IN 1852 REPORTED THE ORIGIN OF THE LAND SURVEY ON MOUNT DIABLO WAS 3 FEET FROM A COAST SURVEY STATION. HE IS OF THE OPINION THAT THE ROCK WHICH CONTAINED THE LAND OFFICE POINT HAS BEEN CUT AWAY, AND THAT THE POINT IS LOST. HE IS OF THE OPINION THAT IT WAS NOT IDENTICAL WITH THE TRIANGULATION STATION. |
| 1/1/1946 by CGS (GOOD) |
| RECOVERY NOTE BY COAST AND GEODETIC SURVEY 1946 (SPH)
SINCE THE 1935 RECOVERY OF THIS STATION A LARGE CONCRETE BUILDING, WITH OBSERVATION TOWER, HAS BEEN ERECTED OVER IT. A FLASHING, RED BEACON LIGHT, ABOUT 40 FEET DIRECTLY ABOVE THE STATION MARK, IS ON THE APEX OF THE TOWER.
THE STATION MARK, UNSTAMPED, IS A BRASS BOLT, 1/2 INCH IN DIAMETER, PROJECTING 1/2 INCH ABOVE THE BASEMENT FLOOR OF THE TOWER, WHICH IS THE SOUTHERN PART OF THE BUILDING. A TAPERED, OCTAGONAL, CONCRETE SHAFT, HOLLOW IN THE CENTER, HAS BEEN ERECTED OVER THE MARK AND EXTENDS INTO THE SECOND STORY OF THE TOWER. TWO OPENINGS, 8 INCHES SQUARE, ARE AT THE BASE OF THE SHAFT AND AT THE LEVEL WITH THE MARK. OBSERVATIONS MUST BE MADE FROM THE THIRD (TOP) STORY, AND A ROUND OPENING, 10 INCHES IN DIAMETER, IS IN THE CENTER OF THE FLOOR TO ENABLE PLUMBING TO THE MARK. OBSERVATIONS WERE MADE FROM A 4 FOOT STAND 7.5 METERS ABOVE THE MARK.
REFERENCE MARK NO. 1, STAMPED MT DIABLO NO 1 1946, IS A STANDARD DISK SET IN THE OUTSIDE PART OF THE SOUTH WINDOW SILL. IT IS ABOUT 1 METER HIGHER THAN THE FLOOR OF THE OBSERVATION ROOM.
REFERENCE MARK NO. 2, STAMPED MT DIABLO NO 2 1946, IS A STANDARD DISK SET IN THE OUTSIDE PART OF THE WEST WINDOW SILL.
THE AZIMUTH MARK, STAMPED MT DIABLO 1946, IS A STANDARD DISK SET IN A CONCRETE CYLINDER, 11 INCHES IN DIAMETER, PROJECTING 6 INCHES ABOVE THE SURFACE OF THE GROUND. IT IS SLIGHTLY SOUTH OF THE CREST OF THE RIDGE, ABOUT 1/2 MILE SOUTHWEST OF THE STATION, 1.6 MILES NORTHEAST BY ROAD FROM THE JUNCTION OF THE ROADS FROM DANVILLE AND WALNUT CREEK, AND 0.1 MILE WEST OF THE ROAD ENROUTE TO THE SUMMIT. IT IS 16 FEET NORTHWEST OF THE THIRD TELEPHONE POLE WEST OF THE ROAD TO THE SUMMIT.
THE STATION CAN BE REACHED BY FOLLOWING ROAD SIGNS FROM THE VICINITY OF WALNUT CREEK OR DANVILLE. |
| 1/1/1948 by CGS (GOOD) |
| RECOVERY NOTE BY COAST AND GEODETIC SURVEY 1948 (CTH)
THE STATION WAS RECOVERED AS PER THE 1946 DESCRIPTION. ALL MARKS WERE IN GOOD CONDITION. |
| 1/1/1951 by CGS (GOOD) |
| RECOVERY NOTE BY COAST AND GEODETIC SURVEY 1951 (JCE)
THE 1935 DESCRIPTION OF THE STATION AND MARKS WAS IMPOSSIBLE TO CHECK BECAUSE OF EXTENSIVE GRADING AND BUILDING, ON THE STATION HILL, SINCE THAT DATE. A NEW DESCRIPTION FOLLOWS--
THE STATION IS LOCATED ON THE SUMMIT OF MOUNT DIABLE AND IN THE BASEMENT OF A LARGE STONE AND CONCRETE BUILDING. THE STATION IS OBSERVED FROM THE GLASS INCLOSED LOOKOUT TOWER WHICH IS REACHED BY TRAP DOOR FROM THE LOOKOUT PLATFORM ON THE ROOF OF THE BUILDING. ON THE SUMMIT OF THE LOOKOUT TOWER IS AN AIRWAY BEACON AND FLASHING RED LIGHT. THE STAND MAY BE CENTERED BY MEANS OF A PLUMB BOB AND 30 FOOT STRING. A KEY TO THE TRAP DOOR MAY BE OBTAINED FROM THE STATE PARK HEADQUARTERS ON THE WAY TO THE STATION. A KEY WILL ALSO BE NEEDED TO PROVIDE ENTRANCE TO THE BASEMENT AND ACCESS TO THE STATION MARK.
THE STATION IS THE CENTER OF A SQUARE HEADED BOLT WHICH IS SET INTO A DRILL HOLE IN SOLID ROCK. THIS MARK IS SURROUNDED BY A CONCRETE PILLAR WHICH IS ABOUT 8 FEET IN DIAMETER AND ABOUT 15 FEET IN HEIGHT. OPENINGS, AT THE BASE OF THE PILLAR, PROVIDE A VIEW OF THE STATION MARK.
REFERENCE MARK NUMBER 1 IS A STANDARD DISK, STAMPED MT. DIABLO NO 1 1946, SET INTO A DRILL HOLE IN THE STONE SILL OF THE LOOKOUT TOWER.
REFERENCE MARK NUMBER 2 IS A STANDARD DISK, STAMPED MT. DIABLO NO 2 1946, SET INTO A DRILL HOLE IN THE STONE SILL OF THE LOOKOUT TOWER.
NO AZIMUTH MARK WAS SEARCHED FOR OR RECOVERED. |
| 1/1/1957 by CGS (GOOD) |
| RECOVERY NOTE BY COAST AND GEODETIC SURVEY 1957 (RLE)
THE STATION MARK, REFERENCE MARKS 1 AND 2 AND THE AZIMUTH MARK WERE RECOVERED AS DESCRIBED AND IN GOOD CONDITION.
A LARGE CONCRETE BUILDING WITH A THREE STORY OBSERVATION TOWER HAS BEEN ERECTED OVER THE MARK. A FLASHING RED BEACON LIGHT, ABOUT 40 FEET DIRECTLY ABOVE THE STATION MARK, IS ON THE APEX OF THE TOWER.
THE STATION MARK, UNSTAMPED, IS A BRASS BOLT, 1/2 INCH IN DIAMETER, PROJECTING ABOUT 1/2 INCH ABOVE THE BASEMENT FLOOR OF THE TOWER, WHICH IS THE SOUTHERN PART OF THE BUILDING. A TAPERED, OCTAGONAL, CONCRETE SHAFT, HOLLOW IN THE CENTER, HAS BEEN ERECTED OVER THE MARK AND EXTENDS INTO THE SECOND STORY OF THE TOWER. TWO OPENINGS, 8 INCHES SQUARE, ARE AT THE BASE OF THE SHAFT TO ENABLE PLUMBING OF THE MARK. OBSERVATIONS MUST BE MADE FROM THE THIRD (TOP) STORY. A ROUND OPENING, 10 INCHES IN DIAMETER, IS IN THE CENTER OF THE TOP FLOOR TO ENABLE PLUMBING TO THE MARK. OBSERVATIONS WERE MADE FROM A 4 FOOT STAND ABOUT 7.5 METERS ABOVE THE MARK.
REFERENCE MARK NO 1, A STANDARD DISK STAMPED MT DIABLO NO 1 1946, IS SET IN A DRILL HOLE IN THE OUTSIDE CONCRETE WINDOW SILL. IT IS ABOUT 1 METER HIGHER THAN THE FLOOR OF THE OBSERVATION ROOM.
REFERENCE MARK NO 2, A STANDARD DISK STAMPED MT DIABLO NO 2 1946, IS SET IN A DRILL HOLE IN THE OUTSIDE CONCRETE WINDOW SILL. IT IS ABOUT 1 METER HIGHER THAN THE FLOOR OF THE OBSERVATION ROOM.
THE AZIMUTH MARK, A STANDARD DISK STAMPED MT DIABLO 1946, IS SET IN THE TOP OF A 12 INCH CONCRETE CYLINDER PROJECTING ABOUT 6 INCHES ABOVE THE SURFACE OF THE GROUND. IT IS SLIGHTLY SOUTH OF THE CREST OF THE RIDGE, 0.1 MILE WEST OF THE BLACKTOP ROAD LEADING TO THE STATION AND LOOKOUT TOWER AND 17 FEET NORTHWEST OF THE THIRD POWERLINE POLE WEST OF THE BLACKTOP ROAD LEADING TO THE STATION.
TO REACH THE STATION FROM THE INTERSECTION OF STATE HIGHWAY 21 AND DIABLO STREET IN DANVILLE, GO EASTERLY ON DIABLO STREET FOR 0.75 MILE TO A FORK AND SIGN MT. DIABLO 14. TAKE THE LEFT FORK AND GO 1.1 MILES TO A FORK AND SIGN MT. DIABLO 13. TAKE THE RIGHT FORK AND GO 0.6 MILE TO A THREE WAY FORK AND SIGN MT. DIABLO 12. TAKE THE CENTER ONE OF THREE FORKS AND GO 8.8 MILES TO A POWERLINE, A TRACK ROAD AND THE AZIMUTH MARK 0.1 MILE WEST ON THE TRACK ROAD. CONTINUE ON THE BLACKTOP ROAD FOR 2.8 MILES TO THE STATION AND LOOKOUT TOWER. |
| 1/1/1960 by CGS (GOOD) |
| RECOVERY NOTE BY COAST AND GEODETIC SURVEY 1960 (IRR)
THE STATION MARK, AZIMUTH MARK, AND REFERENCE MARKS NUMBER 1 AND 2 (SET IN THE CONCRETE WINDOW SILLS OF THE OBSERVATION TOWER) WERE RECOVERED IN GOOD CONDITION AND THE 1946, 1951, AND 1957 DESCRIPTIONS ARE ADEQUATE.
AN UNSTAMPED REFERENCE MARK DISK ABOUT 48 FEET FROM THE STATION IN AZIMUTH ABOUT 78 DEG WAS REMOVED FROM A CONCRETE FLAGPOLE BASE PRIOR TO THE REMOVAL OF THE BASE BY THE STATE DIVISION OF BEACHES AND PARKS. |
| 1/1/1962 by CGS (GOOD) |
| RECOVERY NOTE BY COAST AND GEODETIC SURVEY 1962 (IRR)
THE STATION MARK, AZIMUTH MARK, AND REFERENCE MARKS WERE RECOVERED IN GOOD CONDITION AND THE PREVIOUS DESCRIPTIONS ARE ADEQUATE. |
| 1/1/1963 by CGS (GOOD) |
| RECOVERY NOTE BY COAST AND GEODETIC SURVEY 1963 (LGB)
THE STATION MARK, REFERENCE MARKS 1, 2 AND THE AZIMUTH MARK WERE RECOVERED AS DESCRIBED AND FOUND TO BE IN GOOD CONDITION. NO LOCAL DISPLACEMENT OF THE MARKS WAS NOTED. THE DISTANCE AND DIRECTION TO THE REFERENCE MARKS WERE CHECKED AND FOUND TO BE CORRECT.
THE 1957 DESCRIPTION IS ADEQUATE EXCEPT FOR THE TO REACH. THE FOLLOWING IS A NEW TO REACH TO THE STATION.
TO REACH THE STATION FROM THE INTERSECTION OF STATE HIGHWAY 21 AND DIABLO STREET IN DANVILLE, GO EASTERLY ON DIABLO STREET FOR 0.75 MILE TO A FORK. TAKE LEFT FORK AND CONTINUE EASTERLY FOR 1.1 MILES TO A FORK. TAKE RIGHT FORK AND CONTINUE EASTERLY FOR 0.6 MILE TO A FORK AT THE ENTRANCE TO MT. DIABLO STATE PARK. TAKE LEFT FORK AND GO NORTH AND EAST UPHILL FOR 3.7 MILES TO A LOCKED GATE. (THIS GATE IS LOCKED AT 10--00 P.M. IN THE EVENINGS THE KEY CAN BE OBTAINED FROM THE MT. DIABLO STATE PARK COMMISSION.) PASS THROUGH THE GATE AND CONTINUE NORTH AND EAST UPHILL FOR 4.7 MILES TO A POWERLINE, A TRACK ROAD AND THE AZIMUTH MARK 0.1 MILE SOUTH ON THE TRACK ROAD. CONTINUE NORTH AND EAST UPHILL FOR 2.8 MILES TO STATION AND LOOKOUT TOWER.
THE SAME KEY WILL FIT THE LOCKED DOOR TO GET TO THE STATION MARK THAT IS USED TO GET THROUGH THE LOCKED GATE.
OBSERVATIONS MADE FROM A 4 FOOT STAND INSIDE OF THE LOOKOUT TOWER. |
| 1/1/1969 by CGS (GOOD) |
| RECOVERY NOTE BY COAST AND GEODETIC SURVEY 1969 (WFF)
THE STATION WAS RECOVERED AS DESCRIBED AND THE DESCRIPTION TO REACH THE STATION IS ADEQUATE.
AIRLINE DISTANCE AND DIRECTION FROM NEAREST TOWN ABOUT SEVEN MILES NE OF DANVILLE. |
| 1/1/1969 by CGS (GOOD) |
| RECOVERY NOTE BY COAST AND GEODETIC SURVEY 1969 (CAA)
THE STATION MARK, REFERENCE MARKS 1 AND 2 AND THE AZIMUTH MARK WERE RECOVERED AND FOUND IN GOOD CONDITION, DUE TO CHANGES IN THE ROADS A NEW AND COMPLETE DESCRIPTION FOLLOWS.
TO REACH FROM THE POST OFFICE IN DANVILLE WHICH IS IN THE DANVILLE SQUARE SHOPPING CENTER, GO EASTERLY FOR 0.1 MILE TO HARTZ AVENUE, TURN RIGHT ON HARTZ AVENUE AND GO SOUTHERLY FOR 0.1 MILE TO THE JUNCTION OF DIABLO ROAD, TURN LEFT ON DIABLE ROAD AND GO EASTERLY ON DAIBLE ROAD FOR 0.7 MILE TO A FORK (PASSING UNDER INTERSTATE HIGHWAY 680). TAKE THE LEFT FORK AS PER SIGN MT DIABLO 14 FOR 1.7 MILE TO A FORK. TAKE THE RIGHT FORK AS PER SIGN MT DIABLO 13 FOR 0.9 MILE TO A FORK. TAKE THE LEFT FORK AS PER SIGN MT DIABLO 12 FOR 3.85 MILES TO THE ENTRANCE TO THE MT DIABLO STATE PARK. CONTINUE FOR 3.1 MILES TO A JUNCTION AND A RANGER STATION ON THE LEFT. TURN SHARP RIGHT AS PER SIGN SUMMIT AND GO 1.75 MILES TO WHERE THE ROAD MAKES A SHARP CURVE TO THE RIGHT, A POWER LINE ON THE LEFT AND A TURN AROUND,(TURN LEFT ON THE TURN AROUND AND GO FOR 0.05 MILE TO THE END OF TURN AROUND, CONTINUE AHEAD DOWN GRADE FOR 0.1 MILE TO THE AZIMUTH MARK). CONTINUE ON MAIN ROAD FOR 2.8 MILES TO THE SUMMIT, ROCK LOOKOUT HOUSE AND STATION.
STATION MARK, UNSTAMPED, IS A BRASS BOLT, 1/2 INCH IN DIAMETER, PROJECTING ABOUT 1/2 INCH ABOVE THE BASEMENT FLOOR OF THE TOWER, WHICH IS THE SOUTHERN PART OF THE BUILDING. A TAPERED, OCTAGONAL, CONCRETE SHAFT, HOLLOW IN THE CENTER, HAS BEEN ERECTED OVER THE MARK AND EXTENDS INTO THE SECOND STORY OF THE TOWER, TWO OPENINGS, 8 INCHES SQUARE, ARE AT THE BASE OF THE SHAFT TO ENABLE PLUMBING OF THE MARK. OBSERVATIONS MUST BE MADE FROM THE THIRD (TOP) STORY. A 10 INCH OPENING (ROUND) IS IN THE CENTER OF THE TOP FLOOR TO ENABLE PLUMBING TO THE MARK.
REFERENCE MARK 1 IS A STANDARD DISK, STAMPED MT DIABLO NO 1 1946, IS SET IN A DRILL HOLE IN THE OUTSIDE WINDOW SILL. IT IS ABOUT 1 METER HIGHER THAN THE FLOOR OF THE OBSERVATION TOWER.
REFERENCE MARK 2 IS A STANDARD DISK, STAMPED MT DIABLO NO 2 1946, IS SET IN A DRILL HOLE IN THE OUTSIDE WINDOW SILL. IT IS ABOUT 1 METER HIGHER THAN THE FLOOR OF THE OBSERVATION TOWER.
AZIMUTH MARK IS A STANDARD DISK, STAMPED MT DIABLO 1946, IS SET IN THE TOP OF A 12 INCH ROUND CONCRETE CYLINDER, PROJECTING ABOUT 6 INCHES ABOVE THE SURFACE OF THE GROUND. IT IS SLIGHTLY SOUTH OF THE CREST OF THE RIDGE, 17 FEET WEST OF A POWER LINE POLE.
REFERENCE MARKS ARE TO CLOSE TO FOCUS ON.
HEIGHT OF LIGHT ABOVE STATION MARK 24.74 FEET.
AIRLINE DISTANCE AND DIRECTION FROM NEAREST TOWN 8 MILES NORTHEAST OF DANVILLE. |
| 1/1/1971 by NGS (GOOD) |
| RECOVERY NOTE BY NATIONAL GEODETIC SURVEY 1971 (WMJ)
THE STATION MARK, REFERENCE MARKS 1 AND 2, AND THE AZIMUTH MARK WERE RECOVERED AND FOUND IN GOOD CONDITION. THE DISTANCE AND DIRECTION TO THE REFERENCE MARKS COMPARED FAVORABLY WITH THE 1935 DATA. DUE TO CHANGES IN THE AREA A COMPLETE NEW DESCRIPTION FOLLOWS--
THE STATION IS LOCATED ABOUT 15 MILES NORTHEAST OF DANVILLE, 15 MILES EAST OF WALNUT CREEK, ON THE SUMMIT OF MT. DIABLO AND IN THE CENTER OF THE FIRST FLOOR OF THE MT. DIABLO LOOKOUT TOWER.
TO REACH THE STATION FROM THE INTERSECTION OF HARTZ AVENUE AND DIABLO STREET IN DANVILLE GO EASTERLY ON DIABLO STREET FOR 0.75 MILE TO A FORK AND SIGN, MT DIABLO 14. TAKE THE LEFT FORK AND CONTINUE EASTERLY ON DIABLO STREET FOR 1.1 MILES TO A FORK AND SIGN, MT DIABLO 14. TAKE THE RIGHT FORK AND GO EASTERLY ON DIABLO STREET FOR 0.7 MILE TO A FORK AND SIGN, MT DIABLO 12. TAKE THE RIGHT FORK AND CONTINUE EASTERLY ON DIABLO STREET FOR 0.95 MILE TO A FORK AND SIGN, DIABLO SCENIC BOULEVARD= MT DIABLO 12. TAKE THE LEFT FORK AND CONTINUE EASTERLY ON DIABLO SCENIC BOULEVARD FOR 4.0 MILES TO THE SOUTH GATE RANGER STATION. CONTINUE UPHILL ON THE SURFACED ROAD FOR 3.25 MILES TO RANGER HEADQUARTERS ON THE LEFT. TURN SHARP RIGHT AND CONTINUE UPHILL ON THE MAIN ROAD AS PER SIGN, SUMMIT 4.5, FOR 1.85 MILES TO A GRAVELED SIDE ROAD LEFT. (TO REACH THE AZIMUTH MARK, TURN LEFT AND GO SOUTHWEST ON THE GRAVELED ROAD FOR 0.05 MILE TO THE SOUTHWEST END OF A PARKING AREA. CONTINUE SOUTHWEST ON A TRACK ROAD FOR 0.05 MILE TO A POWER POLE AND THE MARK.) CONTINUE UPHILL ON THE MAIN ROAD FOR 3.0 MILES TO THE SUMMIT OF THE MOUNTAIN, A LOOKOUT TOWER AND THE MARK AS DESCRIBED.
THE STATION MARK IS A 1/2-INCH IN DIAMETER BRASS BOLT THAT PROJECTS 1/2-INCH ABOVE THE GROUND FLOOR OF THE LOOKOUT TOWER. A TAPERED, OCTANGONAL, CONCRETE SHAFT WITH AN 8-INCH OPENING IN THE CENTER HAS BEEN ERECTED OVER THE MARK. TWO OPENINGS IN THE BASE OF THE SHAFT ENABLE PLUMING OF THE MARK. OBSERVATIONS MUST BE MADE FROM THE THIRD STORY OF THE TOWER. A 10-INCH HOLE IN THE FLOOR ENABLES THE PLUMING OF THE MARK.
REFERENCE MARK 1 IS A STANDARD DISK STAMPED MT DIABLO NO 1 1946, CEMENTED IN A DRILL HOLE IN THE OUTSIDE CONCRETE WINDOW SILL OF THE BUILDING. IT IS ON THE SOUTHEAST SIDE OF THE BUILDING AND ABOUT 3 FEET ABOVE THE OBSERVATION ROOM FLOOR.
REFERENCE MARK 2 IS A STANDARD DISK STAMPED MT DIABLO NO 2 1946, CEMENTED IN A DRILL HOLE IN THE OUTSIDE CONCRETE WINDOW SILL OF THE BUILDING. IT IS ON THE WEST SIDE OF THE BUILDING AND ABOUT 3 FEET ABOVE THE OBSERVATION ROOM FLOOR.
THE AZIMUTH MARK IS A STANDARD DISK STAMPED MT DIABLO 1946, SET IN THE TOP OF A ROUND CONCRETE MONUMENT THAT IS 12-INCHES IN DIAMETER AND PROJECTS 6 INCHES ABOVE THE GROUND SURFACE. IT IS 17 FEET NORTHWEST OF THE THIRD POWER LINE POLE WEST OF THE SURFACED ROAD.
AIRLINE DISTANCE AND DIRECTION FROM NEAREST TOWN--15 MILES NORTHEAST OF DANVILLE |
| 1/1/1973 by NGS (GOOD) |
| RECOVERY NOTE BY NATIONAL GEODETIC SURVEY 1973 (CLN)
THE STATION MARK, AZIMUTH MARK, AND REFERENCE MARKS 1 AND 2 WERE RECOVERED IN GOOD CONDITION AND THE PREVIOUS DESCRIPTIONS ARE ADEQUATE.
AIRLINE DISTANCE AND DIRECTION FROM NEAREST TOWN--6 MILES NORTHEAST OF DANVILLE |
| 1/1/1977 by NGS (GOOD) |
| RECOVERY NOTE BY NATIONAL GEODETIC SURVEY 1977 (CA)
THE STATION WAS RECOVERED IN GOOD CONDITION AS PREVIOUSLY DESCRIBED. THE 1946, 1951, AND 1957 DESCRIPTIONS ARE ADEQUATE. THE REFERENCE MARKS WERE NOT SEARCHED FOR. |
| 3/3/1988 by NOS (GOOD) |
| RECOVERY NOTE BY NATIONAL OCEAN SERVICE 1988 (FRD)
THE STATION WAS RECOVERED AT THIS DATE. REFERENCE MARKS 1 AND 2 WERE RECOVERED IN GOOD CONDITION. THE 1971 DESCRIPTION IS ADEQUATE EXCEPT THAT OBSERVATIONS ARE NOT POSSIBLE FROM THE THIRD STORY WHICH IS NOW A RADIO ROOM. A MONUMENT HAS BEEN ERECTED ON THE SECOND FLOOR WHICH PREVENTS PLUMBING THE MARK FROM ABOVE.$DESCRIBED BY T.K. PORTA |
| 1/1/1990 by LOCSUR (GOOD) |
| RECOVERY NOTE BY LOCAL SURVEYOR (INDIVIDUAL OR FIRM) 1990 (BRH)
THE STATION WAS RECOVERED IN GOOD CONDITION AS DESCRIBED. |
| 7/15/1992 by GREENW (GOOD) |
| RECOVERY NOTE BY RONALD GREENWELL 1992
THE STATION WAS RECOVERED IN GOOD CONDITION AS DESCRIBED. |
| 1/1/1997 by USPSQD (GOOD) |
| RECOVERY NOTE BY US POWER SQUADRON 1997
RECOVERED IN GOOD CONDITION. |
